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Troubleshooting

1. Troubleshooting Faulty Cooling Systen Check amount of air blown Is there enough air blown YES Check blower for rotation l Does blower rotate NO Measure voltage between Y BI lead and body ground at motor Sealing band disconnected NO f No 14 fuse blown r Is 12 volts available Evaporator freezed YES Open circuit in or wire harness Mode control cable Faulty fan switch misadjusted ar Check compressor clutch nPop arpune engagement is clutch engagement NO im oe Check clutch condition Wee Compressor belt slip or Abnormal pressure See page 24 13 Is clutch engaged See page 24 9 Weak battery or Shorted clutch coil or Oily substance on pressure plate 24 7 Troubleshooting Electrical Troubleshooting 1 Compressor clutch isn t engaged when A C switch is turned on 4 Check 45A main fuse Is it normal Replace and recheck Check No 13 15A fuse i 4 N Is it normal si Repalce and recheck Y ES Check No 14 20A fuse Is it normal YES Disconnect wire harness from pressure switch 2 Connect two lead to each other on wire harness side Disconnect wire harness from compressor clutch Replace and recheck Turn ignition switch on Turn fan switch on WIRE HARNESS Turn A C switch on ae NOTE If the condenser fan is run
2. e is not frosted low pressure gauge indicates vacuum Leaking thermostat Frozen expansion valve Faulty expansion valve Repair or replace Suction low pres sure abnormally low Test on page 24 27 Excessive bubbles in sight glass condenser is not heated Insufficient refrigerant Check for leaks Charge as required Expansion valve is not frosted and low pressure line is not cooled Low pressure gauge indicates vacuum Outlet temperature is low no air flow Leaking thermostat Frozen expansion valve Faulty expansion valve Replace expansion valve Frozen evaporator Run the fan with compressor off Expansion valve frosted Clogged expansion valve Clean or replace Low pressure hose is cooler than expansion valve outlet and evapora tor Collapsed or restricted low pressure hose Clean repair or replace Suction low pres sure abnormally high Test on page 24 27 Ree att 8 ee Low pressure hose and check joint are cooler than around evaporator Expansion valve open too long Loose thermostat poor contact Repair or replace Suction pressure is lowered when condenser is cooled by water High pressure side also heated Excessive refrigerant in system Discharge refrigerant as necessary High and low pressures are balanced too early when compressor is stopped Faulty gasket Fault
3. ire harnesses are connected Turn ignition switch on Measure voltage between R terminal of 5P connec tor positive and body ground Faulty heater control amplifier Faulty A C switch 24 12 Compressor Troubleshooting TEST RESULTS RELATED SYMPTOMS Discharge high pressure abnormally high Test on page 24 27 After stopping compressor pressure drops to about 195 kPa 2 kg cm 28 psi quickly and then falls gradually PROBABLE CASE REMEDY za Air in system Evacuate system then recharge Evacuation page 24 28 Recharging page 24 29 Pressure does not return to normal when condenser is cooled by water Excessive refrigerant in system Discharge refrigerant as required Reduced air flow through condenser Clogged condenser or radiator fins Original and air conditioner fans not working properly Clean e Check voltage and fan rpm i Discharge pressure abnormally low Test on page 24 27 Line to condenser is excessively hot Restricted flow of refrigerant Repair in system Excessive bubbles in sight glass Insufficient refrigerant in Charge system condenser is not hot system High and low pressures are balanced soon after stopping compressor Faulty compressor dis charge or inlet valve Faulty compressor seal Replace compressor Repair Outlet of expansion valv
4. ning when the A C switch is turned on condenser fan relay diode heater control amplifier Coupe and A C switch are OK Check the clutch relay delay control unit or related circuit Measure voltage between R lead positive and body ground NOTE About 0 5 seconds after turning A C switch on Measure voltage between BI Y lead positive and body ground at clutch relay a Is 12 volts available YES Faulty compressor clutch See page 24 9 24 8 From page 24 8 lt i 12 volts available Open circuit between No 13 YES fuse and clutch relay Measure voltage between R lead positive and body ground at clutch relay Measure voltage between BI Y tama wae weet NOTE The rel h 1 Ddlk ilable NO BI Y lead positive and ane OTE The relays on the S olts available body ground at clutch f brackets are identical To identify observe the lead YES relay R y colors Open circuit between clutch relay and com pressor clutch is 12 volts available Open circuit between No 13 fuse and clutch relay Measure voltage between Y lead positive and body ground at clutch relay il Is voltage bel lt E EE no Turn off all switches YES from delay control unit k Turn ignition switch on Faulty clutch rela g AGY y ee wire harness m Meas
5. olenoid doesn t operate when A C switch is turned on Perform 1 2 of trouble shooting Disconnect wire harness l from idle contro solenoid Perform 3 4 of trouble shooting Measure voltage between wire harness and body ground Is 12 volts available NO Turn off all switches YES Faulty idle control Disconnect wire harness solenoid from delay control unit WIRE HARNESS Check R lead for conti nuity between delay con trol unit and idle control solenoid NO Is there continuity Open circuit YES Check for continuity between BI lead of wire harness and body ground SE NO is there continuity Poor ground Turn ignition switch on Measure voltage between BI Y lead positive of wire harness and body ground Is 12 volts available ue Open circuit between No 13 fuse and delay control unit Turn ignition switch off i aN See page 24 12 24 11 Troubleshooting Electrical Troubleshooting From page 24 11 Perform 5 6 of trouble shooting Measure voltage between wire harness positive and body ground Is 12 volts available Faulty delay control unit Perform 7 8 of No 1 troubleshooting WIRE HARNESS 3 A C switch LED doesn t go on when A C switch is turned on However air conditioner works properly Coupe Remove A C switch from heater control amplifier Make sure other w
6. ure voltage between Y lead positive of wire harness and body ground La Is 12 volts available Measure voltage between BI Y lead positive of wire harness and body ground Is 12 volts available NO YES See page 24 10 Open circuit be tween clutch relay and delay control unit Open circuit be tween No 13 fuse and delay control unit 24 9 Troubleshooting Electrical Troubleshooting From page 24 9 Turn ignition switch off Check for continuity be tween black lead of wire harness and body ground Is there continuity ne YES Pull out Bu R lead from 5 6P connector Poor ground Reconnect connector Short out BI lead and terminal from which Bu R lead was pulled out Turn ignition switch on e gt Measure voltage between R lead positive and body ground at clutch relay NO Faulty delay control unit Is 12 volts available YES Turn ignition switch off 7 Remove A C switch Check A C switch Does switch work NO properly Replace and recheck i Open circuit in Bu R lead between delay control unit and A C switch or faulty thermostat 24 10 Na 2DH B 4D 4DH B Coupe Check Bu R lead for continuity between delay control unit and heater control amplifier Is there continuity Faulty heater control amplifier or thermostat Open circuit a ae D a 2 Idle control s
7. y high pressure valve Foreign particle stuck in high pressure valve Replace compressor 24 13

Troubleshooting

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