Manual AC Heater System.pdf

MANUAL A/C-HEATER SYSTEMArticle Text

2000 Nissan PathfinderFor - - - - -

Copyright © 1998 Mitchell Repair Information Company, LLCWednesday, August 31, 2005 12:44AM

ARTICLE BEGINNING

2000-01 MANUAL A/C-HEATER SYSTEMS

Pathfinder

SPECIFICATIONS

SPECIFICATIONSÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Specification

Compressor Type ................................. Calsonic V6 6-Cyl.Compressor Belt Deflection 2000 Models New Belt ................................ 23/64-25/64" (9-10 mm) Used Belt ................................ 23/64-7/16" (9-11 mm) 2001 Models New Belt .................................. 5/15-23/64" (8-9 mm) Used Belt ................................ 5/26-27/64" (8-10 mm)System Oil Capacity ................................... (1) 6.8 ozs.Refrigerant (R-134a) Capacity ....................... 21.1-24.6 ozs.System Operating Pressures (2) High Side ......................... 178-237 psi (12.5-16.7 kg/cm2) Low Side .............................. 25-36 psi (1.8-2.6 kg/cm2)

(1) - Use Type "S" Oil (Part No. KLH00-PAGS0).(2) - Measured at ambient temperature of 77øF (25øC) with 50-70 percent relative humidity.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY article in GENERAL SERVICING.

DESCRIPTION

A separate evaporator housing assembly is combined with astandard heater core assembly to create an integrated A/C-heatingunit. See Fig. 14. Temperature is regulated by a cable operated airmix door. Air mix door lever connects directly to heater control valvevia heater control rod. Air mix door directs airflow throughevaporator, and then through the heater core to ducting and outlets.When A/C operation is selected, A/C compressor clutch is continuouslyengaged during normal operation.

MANUAL A/C-HEATER SYSTEMArticle Text (p. 2)2000 Nissan PathfinderFor - - - - -Copyright © 1998 Mitchell Repair Information Company, LLC

OPERATION

A/C-HEATER CONTROL PANEL

Desired air control mode is achieved by knob-type controls onA/C-heater control panel. Compressor operation is controlled by A/Cswitch. See Fig. 1. Air intake control (recirculation switch) can beset for recirculation or outside air. A/C switch and blower controlsare independent of mode controls.

Fig. 1: Identifying A/C-Heater Control PanelCourtesy of Nissan Motor Co., U.S.A.

AMBIENT TEMPERATURE SENSOR

2000 Models Ambient temperature sensor, located behind center of grille,turns off when ambient temperature reaches 66øF (19øC) or less, andturns back on when ambient temperature reaches 77øF (25øC) or more.When ambient temperature sensor is closed and A/C is turned on, A/Csystem should operate.

DUAL-PRESSURE SWITCH

2000 Models Dual-pressure switch is mounted on receiver-drier. See Fig. 2. Switch protects A/C system from high pressure build-up due torestriction, overcharge or compressor malfunction. If excessively lowor high system pressure is sensed, the switch electrically stopscompressor clutch operation.

IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE (IACV-FICD)

MANUAL A/C-HEATER SYSTEM

SOLENOID

2000 Models When A/C is turned on, the IACV-FICD solenoid will energize,and additional air will be supplied to engine to compensate for theincreased engine load.

PRESSURE RELIEF VALVE

If high-side pressure exceeds 540 psi (38 kg/cmý), a high-pressure relief valve opens, venting refrigerant to atmosphere.Pressure relief valve is located on compressor. See Fig. 2.

REFRIGERANT PRESSURE SENSOR

2001 Models Refrigerant system is protected against excessively high orlow pressures by the refrigerant pressure sensor, mounted on receiver-drier. See Fig. 2. If system pressure rises above or falls belowspecifications, the sensor detects pressure inside refrigerant lineand sends a voltage signal to the Electronic Control Module (ECM). TheECM controls the A/C relay and will stop the compressor when high-sidepressure rises above 398 psi (28 kg/cmý) or falls below 26 psi (1.8kg/cmý).

Fig. 2: Identifying A/C-Heater System Electrical Components(Engine Compartment)Courtesy of Nissan Motor Co., U.S.A.

MANUAL A/C-HEATER SYSTEMArticle Text (p. 4)2000 Nissan Pathfinder

Fig. 3: Identifying A/C-Heater System Electrical Components(Passenger Compartment)Courtesy of Nissan Motor Co., U.S.A.

ADJUSTMENTS

AIR MIX DOOR CABLE

1) Remove air mix door cable clamp. See Fig. 4. Remove cablefrom air mix door lever. Ensure heater valve control rod is adjustedand operating properly. See HEATER VALVE CONTROL ROD underADJUSTMENTS. Adjust as necessary.


2) Move temperature control knob to maximum HOT position. Setair mix door lever to full HOT position. Attach air mix door cable toair mix door lever. Pull cable cover in the direction of arrow andclamp it in place. Ensure cable operates freely and properly.

Fig. 4: Adjusting Temperature Control Cable (Mode CableAdjustment Is Similar)Courtesy of Nissan Motor Co., U.S.A.

HEATER VALVE CONTROL ROD

NOTE: Air mix door cable must be disconnected prior to adjusting heater valve control rod. See AIR MIX DOOR CABLE. Afteradjusting heater valve control rod, adjust air mix door cable.

Push air mix door lever forward. Pull control rod indirection of arrow. See Fig. 5. Measure clearance between control rodand link lever. Clearance should be about .08" (2 mm). If necessary,adjust clearance and connect rod to air mix door lever. Ensure heatervalve control rod operates smoothly and properly. Install and adjustair mix door cable.

Fig. 5: Adjusting Temperature Control RodCourtesy of Nissan Motor Co., U.S.A.


INTAKE DOOR MOTOR

Ensure intake door motor is installed on intake unit, andintake door motor lever is fitted into slot of intake door link.Connect intake door motor wiring harness connector. Turn ignition on.Turn recirculation switch on and off to verify intake door operatesproperly. If intake door motor does not function, seeINTAKE DOOR MOTOR CIRCUIT under SYSTEM TESTS.

MODE CONTROL CABLE

Turn mode control knob to defrost position. Manually moveside link to defrost position by hand and hold. Connect mode controlcable and pull cover away from side link and secure with clip. SeeFig. 4. Ensure mode door operates properly after connecting cable.

TROUBLE SHOOTING

A/C COMPRESSOR CLUTCH DOES NOT ENGAGE

1) Start engine. Set blower speed to high. Turn A/C on.Verify light on A/C switch is on. 2) Check compressor belt deflection. See SPECIFICATIONS.Adjust or replace compressor belt. If belt is okay, go to next step. 3) Check A/C refrigerant pressure. See A/C SYSTEM PERFORMANCEunder SYSTEM TESTS. If A/C refrigerant pressure is correct, check A/Ccompressor clutch circuit. See A/C COMPRESSOR CLUTCH CIRCUIT underSYSTEM TESTS.

AIR OUTLET DOES NOT CHANGE BETWEEN VENT, BI-LEVEL OR FOOT MODE

1) Depress recirculation switch. Verify light onrecirculation switch is on. Listen for intake door position to change(slight change in sound). Verify recirculation switch turns off whenmode control knob is rotated to defrost position or foot/defrostposition. 2) If system functions as specified, system is okay at thistime. If system does not function as specified, perform intake doormotor circuit test. See INTAKE DOOR MOTOR CIRCUIT under SYSTEM TESTS.If after performing intake door motor circuit test, symptom stillpersists, perform a system operational check and check for othersymptoms. See OPERATIONAL CHECK.

AIR OUTLET DOES NOT CHANGE

1) Turn ignition and blower control switch on. If air doesnot come out of correct outlet, or if air distribution ratio is not as


specified, adjust mode control cable. See AIR DISTRIBUTION RATIOStable. See MODE CONTROL CABLE under ADJUSTMENTS. 2) If air comes out of correct duct and air distributionratio is as specified, no problem is indicated at this time. If afteradjusting mode control cable, symptom still persists, perform a systemoperational check and check for other symptoms. See OPERATIONAL CHECK.

AIR DISTRIBUTION RATIOSÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄSwitch Position Distribution

Vent ........................................... 100% VentBi-Level .............................. 60% Vent; 40% FootFoot ............................... 80% Foot; 20% DefrostFoot/Defrost ....................... 60% Foot; 40% DefrostDefrost ..................................... 100% DefrostÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

BLOWER MOTOR INOPERATIVE

1) Rotate blower control knob through all 4 speeds. Verifyblower speed increases appropriately. Leave blower at high speed. Ifsystem functions as specified, system is okay at this time. If systemdoes not function as specified, perform blower motor circuit test. SeeBLOWER MOTOR CIRCUIT under SYSTEM TESTS. If after performing blowermotor circuit test, symptom still persists, perform a systemoperational check and check for other symptoms. See OPERATIONAL CHECK.

INSUFFICIENT COOLING

1) Start engine. Rotate blower control knob to high. Turn A/Con. Turn temperature knob to full cold position. Check for cold air atdischarge air outlets. If system functions as specified, system isokay at this time. If system does not function as specified, go tonext step. 2) Check compressor belt tension. See SPECIFICATIONS. Adjustor replace as necessary. If belt tension is okay, check temperaturecontrol door operation. Adjust air mix door cable as necessary. SeeAIR MIX DOOR CABLE under ADJUSTMENTS. If temperature control door isokay, check engine cooling fan operation. Repair or replace asnecessary. If cooling fan is okay, go to next step. 3) Check for correct refrigerant level. See SPECIFICATIONS.If refrigerant level is okay, check for evaporator coil freeze up. Ifevaporator coil is freezing up, replace A/C compressor. SeeA/C COMPRESSOR under REMOVAL & INSTALLATION. If A/C compressor isokay, check for air leaks in ducting. 4) If symptom still persists, perform a system operationalcheck. See OPERATIONAL CHECK.


INSUFFICIENT HEATING

1) Start engine and let idle. Turn blower on. Select floormode. Move temperature control knob to full hot position. If hot airdoes not flow from floor vents, check for proper coolant level,restricted or leaking hoses, faulty radiator cap or air in coolingsystem. Repair cooling system as necessary. If cooling system is okay,go to next step. 2) Check heater valve control rod adjustment. SeeHEATER VALVE CONTROL ROD under ADJUSTMENTS. Adjust or replace asnecessary. If heater valve control rod adjustment is okay, go to nextstep. 3) Check air mix door cable adjustment. SeeAIR MIX DOOR CABLE under ADJUSTMENTS. Adjust or replace as necessary.If air mix door cable adjustment is okay, go to next step. 4) Remove instrument panel. See INSTRUMENT PANEL underREMOVAL & INSTALLATION. Visually inspect air mix door operation. Ifair mix door does not operate properly, replace air mix door. If airmix door operates properly, go to next step. 5) Check for leaking air ducts. Repair or replace asnecessary. If air ducts are okay, go to next step. 6) Start engine and bring to normal operating temperature.Check if inlet and outlet heater hoses feel warm. If both heater hosesare warm, go to next step. If both heater hoses are cold, checkthermostat installation and operation. Replace if necessary. 7) Ensure heater hoses are properly installed. Back flushheater core and fill system with coolant. If both hoses are warm,replace heater core. If inlet hose is warmer than the outlet hose,heating system is operating properly. 8) If symptom still persists, perform a system operationalcheck. See OPERATIONAL CHECK.

NOISE

1) If noise is being produced by blower motor, check fornoise in all modes and temperature settings. If noise is constant,check blower motor for foreign particles. Check blower motor and fanfor wear. Check air discharge ducts for obstructions, foreignmaterials or air leakage. 2) If noise is being produced by compressor, check compressorclutch, pulley and idler pulley. Check disc-to-pulley clearance.Clearance should be 0.012-0.024" (0.3-0.6 mm). Check for correctamount of refrigerant oil in compressor. If all components are okay,replace compressor and accumulator. 3) If noise is being produced by expansion valve, replaceexpansion valve. If noise is being produced by refrigerant lines,check if refrigerant lines are properly affixed. If lines are affixed


properly and are still producing noise, install rubber insulationbetween refrigerant line and vehicle body. 4) If noise is being produced by A/C compressor belt, checkfor loose or worn belt. Adjust or replace belt as necessary. Alsocheck for proper A/C compressor belt pulley alignment.

OPERATIONAL CHECK

1) Ensure engine is running and is at normal operatingtemperature. Check blower motor operation. Rotate blower control knobthrough all 4 blower speeds. Verify blower speed increasesappropriately. Leave blower at highest position. 2) Check discharge air. Rotate knob through all modepositions. Verify all 5 mode positions are functioning appropriately.See AIR DISTRIBUTION RATIOS table. 3) Press recirculation switch. Recirculation indicator lightshould come on. Intake door position should change and blower soundwill change slightly. Verify recirculation is canceled in defrost ordefrost/foot mode position. 4) Check temperature decrease. Set temperature to full coldposition. Verify cold air is discharged at air outlets. 5) Check temperature increase. Set temperature to full hotposition. Verify hot air is discharged at air outlets. 6) Set blower knob to any speed. Depress A/C switch. A/Cindicator light should come on. Verify compressor clutch engages.

SYSTEM TESTS


A/C SYSTEM PERFORMANCE

1) Park vehicle out of direct sunlight. Close all doors. Openhood and driver-side window. Connect A/C manifold gauge set. Determinerelative humidity and ambient air temperature. Insert thermometer atcenter vent outlet. 2) Set temperature control knob to maximum cold setting, setmode control knob to vent position, and depress fresh/recirculated airswitch. Turn blower control switch to highest position. See Fig. 1. 3) After running A/C for at least 10 minutes, checktemperature at center vent outlet and high-side and low-side systempressures. Verify system is operating within specified range. SeeA/C SYSTEM PERFORMANCE DISCHARGE AIR TEMPERATURE andA/C SYSTEM PRESSURES tables.


A/C SYSTEM PERFORMANCE DISCHARGE AIR TEMPERATUREÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄInlet Air Temp. - øF (øC) (1) (2) Outlet Air Temp. - øF (øC)

77 (25) ........................................... 43-54 (6.0-12.2)86 (30) .......................................... 50-63 (10.0-17.2)95 (35) .......................................... 59-75 (15.2-23.8)104 (40) ......................................... 73-90 (22.7-32.2)

(1) - Measure inlet air temperature at blower inlet under right side of instrument panel.(2) - Specification is with relative humidity at 50-70 percent.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

A/C SYSTEM PRESSURESÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄAmbient Air Temp. (1) High-Pressure - (1) Low-Pressure - - øF (øC) psi (kg/cm2) psi (kg/cm2)

77 (25) ............... 178-237 (12.5-16.7) ....... 25-36 (1.8-2.5)86 (30) ............... 206-273 (14.5-19.2) ....... 28-40 (2.0-2.8)95 (35) ............... 240-317 (16.9-22.3) ....... 33-45 (2.3-3.2)104 (40) .............. 279-363 (19.7-25.5) ....... 41-54 (2.9-3.8)

(1) - Specification is with relative humidity at 50-70 percent.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

A/C COMPRESSOR CLUTCH CIRCUIT

2001 Models 1) Disconnect A/C compressor harness connector. Measurevoltage between ground and terminal No. 1 (Black/White wire) of A/Ccompressor clutch harness connector. If battery voltage exists, go tonext step. If battery voltage does not exist, go to step 3). 2) Test A/C clutch coil. If A/C clutch coil is okay, go tonext step. If A/C clutch coil is not okay, replace A/C clutch coil. 3) Remove A/C relay. Check continuity in Black/White wirebetween terminal No. 1 of A/C clutch and terminal No. 5 of A/C relaysocket. If continuity does not exist, repair open in Black/White wire.If continuity exists, check continuity between ground and eitherterminal No. 1 of A/C clutch harness connector or terminal No. 5 ofA/C relay socket. If continuity exists, repair short to ground inBlack/White wire. If continuity does not exist, go to next step. 4) Measure continuity between ground and terminal No. 2 and 3of A/C relay socket. If battery voltage exists, test A/C relay. SeeA/C RELAY under COMPONENT TESTS. If relay is okay, go to next step. Ifrelay is faulty, replace A/C relay. If battery voltage does not exist,


check power distribution to fuse No. 6 of underdash fuse block. 5) Reinstall A/C relay. Check voltage between ground andterminal No. 27 (Light Green wire) of Electronic Control Module (ECM)harness connector. See Fig. 7. If battery voltage exists, go to step7). If battery voltage does not exist, go to next step. 6) Disconnect ECM harness connector. Remove A/C relay. Checkcontinuity between terminal No. 27 (Light Green wire) of ECM harnessconnector and terminal No. 1 (Green/Red wire) of A/C relay socket. Ifcontinuity exists, check for short to ground in Light Green wire orGreen/Red wire. If continuity does not exist, repair open in LightGreen wire or Green/Red wire. 7) Check continuity between ground and terminal No. 45(Black/Red wire) of ECM harness connector. If approximately 4.6 voltsexists, go to next step. If approximately 4.6 volts does not exist,test ECM. See appropriate SELF-DIAGNOSTICS article in ENGINEPERFORMANCE. 8) Disconnect ECM and refrigerant pressure sensor. Testrefrigerant pressure sensor. See REFRIGERANT PRESSURE SENSOR underCOMPONENT TESTS. If refrigerant pressure sensor tests okay, go to nextstep. If refrigerant pressure sensor does not test okay, replacesensor. 9) Disconnect A/C switch harness connector. Check continuitybetween terminal No. 45 (Black/Red wire) of ECM harness connector andterminal No. 2 (Black/White wire) of A/C switch harness connector. SeeFig. 7. If continuity does not exist, repair open in Black/Red wire orBlack/White wire. If continuity exists, check continuity betweenground and terminal No. 2 (Black/White wire) of A/C switch harnessconnector or terminal No. 45 (Black/Red wire) of ECM harnessconnector. If continuity exists, repair short to ground in Black/Redwire or Black/White wire. If continuity does not exist, go to nextstep. 10) Test A/C switch. See A/C SWITCH under COMPONENT TESTS. IfA/C switch tests okay, go to next step. If A/C switch does not testokay, replace A/C switch. 11) Check continuity of Light Green/Red wire between terminalNo. 1 of A/C switch and terminal No. 1 of blower control switch. Ifcontinuity does not exist repair open in Light Green/Red wire. Ifcontinuity exists, check continuity between ground and either terminalNo. 1 of A/C switch or terminal No. 1 of blower control switch. Ifcontinuity exists, repair short to ground in Light Green/Red wire. Ifcontinuity does not exist, go to next step. 12) Check continuity between ground and terminal No. 6 (Blackwire) of blower control switch harness connector. If continuityexists, go to next step. If continuity does not exist, repair open inBlack wire between blower control switch and grounds (located at rightrear corner of engine compartment and driver's kick panel). SeeWIRING DIAGRAMS. 13) Test blower control switch. See BLOWER CONTROL SWITCH


under COMPONENT TESTS. If switch is okay, blower circuit is okay atthis time. If switch is not okay, replace blower control switch.

2000 Models 1) Disconnect A/C compressor harness connector. Measurevoltage between ground and terminal No. 1 (Black/White wire). Ifbattery voltage exists, go to next step. If battery voltage does notexist, go to step 3). 2) Test A/C clutch coil. If A/C clutch coil is okay, go tonext step. If A/C clutch coil is not okay, replace A/C clutch coil. 3) Remove A/C relay. Check continuity in Black/White wirebetween terminal No. 1 (Black/White wire) of A/C clutch and terminalNo. 5 of A/C relay harness connector. If continuity does not exist,repair open in Black/White wire. If continuity exists, checkcontinuity between ground and terminal No. 1 of A/C clutch or terminalNo. 5 of A/C relay harness connector. If continuity exists, repairshort to ground in Black/White wire. If continuity does not exist, goto next step. 4) Check continuity between ground and terminal No. 2 and 3of A/C relay. If battery voltage exists, test A/C relay. See A/C RELAYunder COMPONENT TESTS. If relay is okay, go to next step. If relay isfaulty, replace A/C relay. If battery voltage does not exist, checkpower distribution to fuse No. 6 of underdash fuse block. 5) Reinstall A/C relay. Check voltage between ground andterminal No. 12 (Green/Red) wire of ECM harness connector. See Fig. 6.If battery voltage exists, go to step 7). If battery voltage does notexist, go to next step. 6) Disconnect ECM harness connector. Remove A/C relay. Checkcontinuity of Green/Red wire between terminal No. 12 of ECM harnessconnector and terminal No. 1 of A/C relay socket. If continuityexists, check for short to ground in Green/Red wire. If continuitydoes not exist, repair open in Light Green wire or Green/Red wire. 7) Check continuity between ground and terminal No. 21(Black/White wire) of ECM harness connector. If approximately 4.6volts exists, go to next step. If approximately 4.6 volts does notexist, test ECM. See appropriate SELF-DIAGNOSTICS article in ENGINEPERFORMANCE. 8) Check continuity of Black/White wire between terminal No.21 of ECM and terminal No. 2 of dual-pressure switch. See Fig. 6. Ifcontinuity does not exist, repair open in Black/White wire. Ifcontinuity exists, check continuity between ground and terminal No 21of ECM or terminal No. 2 of dual-pressure switch. If continuityexists, repair short to ground in Black/White wire. If continuity doesnot exist, go to next step. 9) Test dual-pressure switch. See 2000 MODELS under COMPONENTTESTS. If switch is okay, go to next step. If dual-pressure switch isnot okay, replace switch. 10) Check continuity of Blue/Black wire between terminal No.


1 of dual-pressure switch and terminal No. 2 of A/C switch. Ifcontinuity does not exist, repair open in Blue/Black wire. Ifcontinuity exists, check continuity between ground and terminal No. 1of dual-pressure switch or terminal No. 2 of A/C switch. If continuityexists, repair short to ground in Blue/Black wire. If continuity doesnot exist, go to next step. 11) Test A/C switch. See A/C SWITCH under COMPONENT TESTS. Ifswitch tests okay, go to next step. If switch does not test okay,replace A/C switch. 12) Check continuity of Light Green/Red wire between terminalNo. 1 of A/C switch harness connector and terminal No. 1 of blowercontrol switch harness connector. If continuity does not exist, repairopen in Light Green/Red wire. If continuity exists, check continuitybetween ground and terminal No. 1 of A/C switch harness connector orterminal No. 1 of blower control switch harness connector. Ifcontinuity exists, repair short to ground in Light Green/Red wire. Ifcontinuity does not exist, go to next step. 13) Check continuity between ground and terminal No. 6 (Blackwire) of blower control switch harness connector. If continuityexists, go to next step. If continuity does not exist, repair open inBlack wire between blower control switch and grounds (located at rightrear corner of engine compartment and driver's kick panel). SeeWIRING DIAGRAMS. 14) Test blower control switch. See BLOWER CONTROL SWITCHunder COMPONENT TESTS. If switch is okay, blower control circuit isokay at this time. If switch is not okay, replace blower controlswitch.

Fig. 6: Identifying Terminals Of Engine Control Module (ECM)Harness Connector (2000)Courtesy of Nissan Motor Co., U.S.A.

Fig. 7: Identifying Terminals Of Engine Control Module (ECM)Harness Connector (2001)Courtesy of Nissan Motor Co., U.S.A.


BLOWER MOTOR CIRCUIT

1) Disconnect blower motor harness connector. Turn ignitionon. Using a DVOM, check for voltage between ground and terminal No. 1(Blue wire) of blower motor harness connector. If 12 volts exists, goto next step. If 12 volts does not exist, check fuses No. 1 (15-amp)and No. 2 (15-amp) at fuse block. Fuse block is located at lower leftside of instrument panel. If fuse is blown, check for short to groundin Blue wire between blower motor and fuses No. 1 and 2. SeeWIRING DIAGRAMS. If fuses are okay, check continuity in Blue wirebetween terminal No. 1 of lower motor harness connector and fuses No.1 and 2. If continuity does not exist, repair open in Blue wire. 2) Turn ignition off. Place blower control knob at anyposition except off. Check continuity between ground and terminal No.2 (Blue/White wire) of blower motor harness connector. If continuityexists, go to next step. If continuity does not exist, reconnectblower motor harness connector and go to step 4). 3) Test blower motor. See BLOWER MOTOR under COMPONENT TESTS.Replace as necessary. 4) Disconnect blower motor resistor. See Fig. 9. Turnignition on. Using a DVOM, check for voltage between ground andterminal No. 1 (Blue/White wire) of blower motor resistor harnessconnector. If battery voltage does not exist, go to next step. Ifbattery voltage exists, go to step 6). 5) Turn ignition off. Disconnect blower motor harnessconnector. Check continuity in Blue/White wire between terminal No. 2of blower motor harness connector and terminal No. 1 of blower motorresistor harness connector. If continuity does not exist, repair openin Blue/White wire. If continuity exists, check continuity betweenground and terminal No. 2 of blower motor harness connector orterminal No. 1 of blower motor resistor. If continuity exists, repairshort to ground in Blue/White wire. See WIRING DIAGRAMS. If continuitydoes not exist, go to next step. 6) Turn ignition off. Disconnect blower control switchharness connector. Check continuity between ground and terminal No. 6(Black wire) of blower control switch harness connector. If continuityexists, go to next step. If continuity does not exist, repair open orpoor ground connection in Black wire between blower control switchharness connector and grounds (located at right rear corner of enginecompartment and at driver's kick panel). 7) Test blower motor resistor. See BLOWER MOTOR RESISTORunder COMPONENT TESTS. Also, inspect blower motor resistor harnessconnector for good terminal contact. Repair or replace as necessary.If blower resistor and harness connector are okay, go to next step. 8) Install blower motor resistor. Disconnect blower controlswitch harness connector. Turn ignition on. Check for voltage atterminals No. 2, 3, 4 and 5 of blower control switch harness


connector. See Fig. 11. If each reading indicates 12 volts, go to step10). If any reading does not indicate 12 volts, go to next step. 9) Disconnect blower motor resistor harness connector. Checkcontinuity of Blue/Black, Blue/Red, Blue/Yellow and Blue/White wiresbetween blower motor resistor harness connector terminals No. 4, 3, 2and 1 and blower control switch harness connector terminals No. 5, 4,3 and 2. See Figs. 8 and 9. If continuity does not exist in anyspecified circuit, repair as necessary. If continuity exists in eachcircuit, check continuity between ground and terminals No. 4, 3, 2 and1 of blower control switch harness connector. If continuity exists inany of the wires, repair short to ground. If continuity does not existin any of the wires, go to next step. 10) Check blower control switch. See BLOWER CONTROL SWITCHunder COMPONENT TESTS. Replace as necessary.

Fig. 8: Identifying Terminals Of Blower Control Switch HarnessConnectorCourtesy of Nissan Motor Co., U.S.A.

Fig. 9: Identifying Blower Motor Resistor TerminalsCourtesy of Nissan Motor Co., U.S.A.

INTAKE DOOR MOTOR CIRCUIT

1) Disconnect intake door motor. Turn ignition on. Using aDVOM, check for voltage between ground and terminal No. 1 (Green/Redwire) of intake door motor harness connector. If battery voltageexists, go to next step. If battery voltage does not exist, check fuseNo. 11 (7.5-amp) located in fuse block at lower left side of


instrument panel. Replace fuse if blown. If fuse is okay, checkcontinuity of Green/Red wire between fuse No. 11 (7.5-amp) andterminal No. 1 of intake door motor harness connector. If continuityexists, go to next step. If continuity does not exist, repair open inGreen/Red wire. 2) Turn ignition off. Switch to recirculation mode.Continuity should exist between ground and terminal No. 2 (Green/Blackwire) of intake door motor harness connector. Continuity should notexist between ground and terminal No. 3 (Blue/White wire) of intakedoor motor harness connector. Place recirculation switch in freshmode. Continuity should exist between ground and terminal No. 3(Blue/White wire) of intake door motor harness connector. Continuityshould not exist between ground and terminal No. 1 (Green/Black wire)of intake door motor harness connector. If readings are as specified,check intake door motor adjustment. See INTAKE DOOR MOTOR underADJUSTMENTS. If readings are not as specified, go to next step. 3) Disconnect mode control switch harness connector. Checkcontinuity in Blue/White wire and Green/Black wire between terminalsNo. 1 and 2 of mode control switch harness connector and terminals No.2 and 3 of intake door motor harness connector. See WIRING DIAGRAMS.If continuity exists in both circuits, go to next step. If continuitydoes not exist in both circuits, repair open in affected circuit orharness connector. 4) Test mode control switch. See MODE CONTROL SWITCH underCOMPONENT TESTS. Replace as necessary. If mode control switch is okay,go to next step. 5) Disconnect recirculation switch. Check continuity in Blackwire between terminal No. 4 of mode control switch harness connectorand terminal No. 4 of recirculation switch harness connector. Ifcontinuity exists, go to next step. If continuity does not exist,replace mode control switch. 6) Check continuity between ground and terminal No. 4 (Blackwire) of mode control switch harness connector. If continuity exists,go to next step. If continuity does not exist, repair open or poorground connection in Black wire between mode control switch harnessconnector and ground (located at both left and right kick panels). SeeWIRING DIAGRAMS. 7) Check recirculation switch. See RECIRCULATION SWITCH underCOMPONENT TESTS. Replace switch as necessary.

COMPONENT TESTS

A/C SWITCH

Disconnect negative battery cable. Remove A/C switch fromA/C-heater control panel. Check continuity between A/C switchterminals. With A/C switch on (button depressed), continuity should


exist. With A/C switch off (button released), continuity should notexist. If continuity is not as specified, replace A/C switch.

A/C RELAY

1) Remove A/C relay. See Fig. 2. Check continuity between A/Crelay terminals No. 1 and 2. See Fig. 10. Verify continuity exists.Check continuity between relay terminals No. 3 and 5. Continuityshould not exist. 2) Apply battery voltage between relay terminals No. 1 and 2.Continuity should now exist between terminals No. 3 and 5. See Fig. 10. If continuity is not as specified, replace relay.

Fig. 10: Identifying A/C Relay TerminalsCourtesy of Nissan Motor Co., U.S.A.

BLOWER MOTOR

Disconnect wiring harness at blower motor. Apply batteryvoltage across blower motor terminals. Verify blower motor operatessmoothly. If blower motor operation is rough or runs below normalspeed, replace blower motor. Verify there are no foreign particlesinside intake unit.

BLOWER MOTOR RESISTOR

Disconnect blower motor resistor. Check continuity betweenspecified blower motor resistor terminals. See Fig. 9. SeeBLOWER MOTOR RESISTOR VALUES table. If resistance is not as specified,replace blower motor resistor.

BLOWER MOTOR RESISTOR VALUESÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄTerminal No. Ohms

1 & 2 .............................................. .5-.61 & 3 ............................................ 1.4-1.61 & 4 ............................................ 2.5-2.8ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ


BLOWER CONTROL SWITCH

Disconnect blower control switch harness connector. SeeFig. 11. Check for continuity between indicated terminals with blowercontrol switch in specified position. SeeBLOWER CONTROL SWITCH CONTINUITY TEST table. Replace switch ifcontinuity is not as specified.

BLOWER CONTROL SWITCH CONTINUITY TESTÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄKnob Position (1) Continuity Between Terminals No.

Off (0) .............................................. No Continuity1 (I) ..................................................... 1, 5 & 62 (II) .................................................... 1, 4 & 63 (III) ................................................... 1, 3 & 64 (IIII) .................................................. 1, 2 & 6

(1) - See Fig. 1.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

Fig. 11: Identifying Blower Control Switch TerminalsCourtesy of Nissan Motor Co., U.S.A.

DUAL-PRESSURE SWITCH

2000 Models Remove dual-pressure switch harness connector. See Fig. 2.Using ohmmeter, check continuity between switch terminals underspecified conditions. See DUAL-PRESSURE SWITCH TEST table. Replaceswitch if it does not perform as indicated.

DUAL-PRESSURE SWITCH TESTÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄPressure - psi (kg/cmý) System Operation Continuity


Low-Side Pressure Decreasing To 23-28 (1.6-2.0) ........ Off ................. No Increasing To 23-31 (1.6-2.2) ......... On ................ YesHigh-Side Pressure Increasing To 356-412 (25-29) ........ Off ................. No Decreasing To 270-327 (19-23) ......... On ................ YesÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE (IACV-FICD) SOLENOID

2000 Models 1) Start engine and allow to reach normal operatingtemperature. Ensure idle speed is between 700-800 RPM withtransmission in neutral. Adjust idle speed as necessary. Turn A/C andblower control switch on. Ensure idle speed is at 800 RPM or more withtransmission in neutral. If idle speed is as specified, IACV-FICDsolenoid is okay. If idle speed is not as specified, go to next step. 2) Verify A/C compressor is functioning properly. Turn engineoff. Disconnect IACV-FICD solenoid valve harness connector. SeeFig. 12. Start engine. Turn A/C and blower control switch on. Using avoltmeter, check voltage between ground and terminal No. 1(Black/White wire) of IACV-FICD solenoid harness connector. If batteryvoltage exists, go to step 4). If battery voltage does not exist, goto next step. 3) Ensure IACV-FICD solenoid harness connectors, located atright side of engine compartment next to right shock tower, aresecurely connected and free of corrosion. Check continuity inBlack/White wire between terminal No. 1 of IACV-FICD solenoid harnessconnector and in-line harness connector located at left rear of enginecompartment. If continuity does not exist, repair open in Black/Whitewire. If continuity exists, check continuity between ground andterminal No. 1 (Black/White wire) between terminal No. 1 of IACV-FICDsolenoid harness connector. If continuity exists, repair short toground in Black/White wire. See WIRING DIAGRAMS. 4) Ensure engine is at normal operating temperature. Turnignition off. Using an ohmmeter, check continuity in Black wirebetween ground (located at left rear and right front of enginecompartment) and terminal No. 2 of ambient air temperature sensorharness connector. If continuity exists, go to next step. Ifcontinuity does not exist, repair open or poor ground connection inBlack wire. 5) Check continuity in Green/Orange wire between terminal No.1 of ambient air temperature sensor harness connector and terminal No.2 of IACV-FICD solenoid harness connector. If continuity does notexist, repair open in Green/Orange wire. If continuity exists checkcontinuity between ground and either terminal No. 1 of ambient air


temperature sensor or terminal No. 2 of IACV-FICD solenoid harnessconnector. If continuity exists, repair short to ground inGreen/Orange wire. If continuity does not exist, go to next step. 6) Ensure harness connectors, located at right side of enginecompartment next to right shock tower, at left rear of enginecompartment and lower left side of instrument panel, are securelyconnected and free of corrosion. Also verify diode located at leftrear side of engine compartment is okay. Go to next step. 7) Apply battery voltage and ground to IACV-FICD solenoid. Aclicking sound should be heard. Disassemble IACV-FICD solenoid andcheck plunger for seizing or sticking. Also check for a broken spring.Repair or replace as necessary. If IACV-FICD solenoid is okay, replaceambient air temperature sensor.

Fig. 12: Identifying IACV-FICD Solenoid LocationCourtesy of Nissan Motor Co., U.S.A.

MODE CONTROL SWITCH

Disconnect negative battery cable. Disconnect mode door andrecirculation harness connectors. Using an ohmmeter, check for shortor open circuit between terminals No. 1-4 of recirculation switchharness connector and terminals No. 1-4 of mode control switch harnessconnector. See Fig. 13. Rotate mode control knob. If continuity doesnot exist at appropriate terminals, replace mode control switch.


Fig. 13: Testing Mode Control SwitchCourtesy of Nissan Motor Co., U.S.A.

RECIRCULATION SWITCH

Remove recirculation switch from A/C-heater control panel.With recirculation switch on (button depressed), continuity shouldexist between terminals No. 1 and 4 of recirculation switch harnessconnector. See Fig. 13. With recirculation switch off (buttonreleased), continuity should exist between recirculation switchterminals No. 2 and 4. If continuity is not as specified, replacerecirculation switch.

REFRIGERANT PRESSURE SENSOR

2001 Models Voltage output should increase when system pressureincreases. With ambient temperature of 77øF (25øC), check voltage


between ground and terminal No. 81 (White/Purple wire) of ECM harnessconnector. Sensor output voltage should evenly increase from .36 voltsat 26 psi (1.8 kg/cm2) to 4.16 volts at 398 psi (28 kg/cm2). Ifvoltage is not as specified, replace refrigerant pressure sensor. SeeFig. 7.

REMOVAL & INSTALLATION


A/C-HEATER COMPONENTS & DUCTS

CAUTION: New refrigerant connections use different "O" ring configurations. DO NOT interchange "O" rings.

Removal & Installation All "O" rings and "O" ring grooves have been relocated. A newtype of refrigerant connection and component is provided with anidentification mark. For instance, a .39" (10 mm) diameter A/C linewill have a Pink seal or paint mark. When installing, tighten A/C lineflange connections to 14-22 ft. lbs. (20-29 N.m). Immediately plug allopenings after removal of components. Install all NEW "O" rings.Lubricate all "O" rings using refrigerant oil.

Fig. 14: Exploded View Of A/C-Heater System ComponentsCourtesy of Nissan Motor Co., U.S.A.


A/C COMPRESSOR

Removal Disconnect negative battery cable. Loosen idler pulley bolt,and remove compressor belt. Discharge A/C system, using approvedrefrigerant recovery/recycling equipment. Disconnect compressor clutchharness connector. Remove discharge and suction hoses from compressor.Remove compressor bolts and compressor. If replacing A/C compressor,drain and record amount of refrigerant oil from old A/C compressor.

Installation To install, reverse removal procedure. If replacing A/Ccompressor, drain refrigerant oil from compressor. Add amount ofrefrigerant oil recorded from old compressor, using clean refrigerantoil. Tighten mounting bolts to specification. SeeTORQUE SPECIFICATIONS. Use new "O" rings coated with refrigerant oilon all connecting hoses. A normal clanking sound may occasionally beheard from compressor during refrigerant charge. Check for leaks.

INSTRUMENT PANEL

Removal & Installation Disable air bag system. See AIR BAG SYSTEM SAFETY article inGENERAL SERVICING. Remove driver-side air bag module and steeringwheel. Remove left and right kick panels. Remove front pillar garnish.Remove remaining components in order listed in illustration. SeeFig. 15. To install, reverse removal procedure.


Fig. 15: Exploded View Of Instrument PanelCourtesy of Nissan Motor Co., U.S.A.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONSÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ


Application Ft. Lbs. (N.m)

A/C Compressor Bolts ................................. 17-20 (23-27)A/C Compressor Bracket Bolts ......................... 33-44 (45-60)Low-Pressure Hose Fitting ............................ 14-22 (20-29)

INCH Lbs. (N.m)

A/C Compressor Fittings .............................. 69-174 (8-20)Expansion Valve Bolt ................................... 26-43 (3-5)High-Pressure Hose-To-Condenser Fitting .............. 69-174 (8-20)High-Pressure Hose-To-Evaporator Fitting ............... 26-43 (3-5)Low-Pressure Hose-To-Evaporator Fitting .............. 69-174 (8-20)Receiver-Drier Fittings ................................ 26-43 (3-5)Receiver-Drier-To-Condenser Fittings ................. 69-174 (8-20)ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

WIRING DIAGRAMS


Fig. 16: Manual A/C-Heater System Wiring Diagram (2000 Pathfinder)

MANUAL A/C-HEATER SYSTEMArticle Text (p. 27)2000 Nissan PathfinderFor - - - - -Copyright © 1998 Mitchell Repair Information Company, LLCFig. 17: Manual A/C-Heater System Wiring Diagram (2001 Pathfinder)

END OF ARTICLE

Documents

Manual AC Heater System.pdf