A/C Compressor Controls - Troubleshooting Procedures

COMPLAINT VERIFICATION
Go to "Functional Check of the Heating and Air Conditioning System" for a guide to normal operation. System Check of the Heating and Air Conditioning System

TROUBLESHOOTING
Perform the following checks before doing the System Diagnosis.
1. Check Fuse 20 by visual inspection.
2. Check that Compressor Clutch connector is firmly seated.

If OK:
Go to System Diagnosis for diagnostic tests.

SYSTEM DIAGNOSIS
Perform the tests listed for your symptom in the Symptom Table below.





Symptom Table





Test A: A/C Isolation Test





Test B: Compressor Clutch Voltage Test





Test C: Evaporator Temperature Regulator Voltage And Resistance Test (Table 1)





Test C: Evaporator Temperature Regulator Voltage And Resistance Test (Table 2)





Test D: Idle Speed Control Unit Voltage Test





Test C: A/C Select Switch Voltage Test

Test F: Compressor Cycling Test
Check High Pressure Cut-Out Switch.
Check BK wire to terminal 2 of Evaporator Temperature Regulator for an open or short. Repair/Replace as necessary.