Insufficient Or No A/C Cooling
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 article in the ACCESSORIES/SAFETY EQUIPMENT Section.
INSUFFICIENT OR NO A/C COOLING
| Test Step | Result | Action To Take: |
|---|---|---|
| A1 - VERIFY CONDITION | ||
| * Check System Operation | System Cooling Properly | INSTRUCT Driver On How To Use System |
| " | System Not Cooling Properly | Go To A2 |
| A2 - CHECK COOLING FAN | ||
| * Does Vehicle Have An Electro-Drive Cooling Fan? | Yes | Go To A3 |
| " | No | Go To A5 |
| A3 - CHECK A/C COMPRESSOR CLUTCH | ||
| * Does The A/C Compressor Clutch Engage? | Yes | Go To A4 |
| " | No | See Clutch Circuit Diagnosis |
| A4 - CHECK OPERATION OF COOLING FAN | ||
| * Check To Ensure Electro-Drive Cooling Fan Runs When The A/C Compressor Clutch Is Engaged | Yes | Go To A5 |
| " | No | Refer to engine cooling fan circuit diagnosis information in ENGINE COOLING article in the ENGINE COOLING section. |
| A5 - COMPONENT CHECK | ||
Under Hood Check For:
In-Car Check For:
|
Okay But Still Not Cooling Properly | Go To A7 |
| " | Not Okay | Repair And Go To A6 |
| A6 - CHECK SYSTEM OPERATION | ||
| * Check System Operation | Okay | Condition Corrected Go To A1 |
| " | Not Okay | Go To A7 |
| A7 - CHECK COMPRESSOR CLUTCH | ||
* Use Refrigerant System Pressure/Clutch Cycle Rate And Timing Evaluation Charts.
* Check Compressor Clutch OFF/ON; Time With Watch. |
Compressor Cycles Very Rapidly (1 Second On) (1 Second Off) | Go To A8 |
| " | Compressor Runs Continuously (Normal Operation In Ambient Temp. Above 27°C (80°F) Depending On Humidity Conditions) | Go To A9 |
| " | Compressor Cycles Slow | Go To A8 |
| A8 - CHECK CLUTCH CYCLING PRESSURE SWITCH | ||
| * Bypass Clutch Cycling Pressure Switch With Jumper Wire. Compressor on Continuously. * Hand Feel Evaporator Inlet And Tubes. | Outlet Tube Same Temperature (Approximately -2.0°C to -4.0°C Or 28°F To 40°F) Or Slightly Colder Than Inlet Tube (After Fixed Orifice). | REPLACE clutch Cycling Pressure Switch. Do Not Discharge System. Switch Fitting has Schrader Valve. Go To A9 |
| " | Inlet Tube Warm Or (After Fixed Orifice) Colder Than Outlet Tube. | Go To A10 |
| A9 - CHECK SYSTEM PRESSURES | ||
| * Compare Readings W/Normal System Pressure Ranges. Compressor On Continuously | Clutch Cycles Within Limits, System Press. Within Limits. | System Okay Go To A1 |
| " | Compressor Runs Continuously (Normal Operation In Ambient Temp. Above 27°C (80°F) Depending On Humidity Conditions). | Go To A11 |
| " | Compressor Cycles High Or Low ON Above 359 kPa (52 psi), OFF below 144 kPa (21 psi) | REPLACE Clutch Switch. Do Not Discharge System. Switch Fitting Has Schrader Valve. OK-Go To A1. Not OK-Go To A10 |
| A10 - CHECK SYSTEM | ||
| Leak Check System | Leak Found | Repair, Discharge, Evacuate And Charge System. System OK, Go To A1. |
| " | No Leak Found | Low Refrigerant Charge Or Moisture In System. Discharge, Evacuate And Charge System. System OK. |
| A11 - CHECK CLUTCH CYCLING | ||
| Disconnect Blower Motor Wire And Check For Clutch Cycling Off At 144 kPa (21 psi) (Suction Pressure). | Clutch Cycles OFF At 144-179 kPa (21-26 psi) | Connect Blower Motor Wire. System OK, Go To A1. |
| " | Pressure Falls Below 144 kPa (21 psi) | REPLACE Clutch Cycling Pressure Switch. Do Not Discharge System. Switch Fitting Has Schrader Valve. System OK, Go To A1. |