A: Isolation Test

1. Remove the connector from the A/C Cut-Out Relay and check the voltage to ground using a test lamp at the following terrainals of the connector:

^ If tests are good, proceed to step 2.

^ If test lamp does not light at Terminal 2, check PNK/BLK (639) wires (see schematic),

^ If the test lamp does not light at Terminal 1, jumper the Pressure Cycling Switch and the A/C High Pressure Cut-Out Switch harness connectors.

- If test lamp now lights at Terminal 1 of the A/C Cut-Out Relay, check refrigerant charge. If refrigerant charge is good, replace the suspect pressure switch.

- Check LT GRN (66), DK BLU (204) and LT BLU (67) wires for open or short to ground.

- If all checks are good, proceed to Test D: HEATER AND A/C CONTROL ASSEMBLY OUTPUT TEST. D: Heater & A/C Control Assembly Output Test






2. With the connector removed from the A/C Cut-Out Relay, connect a fused jumper between the terminals given in the illustrated table. Note Compressor Clutch action.

^ If the A/C Compressor Clutch engages (loud click), the clutch and A/C Control Assembly circuits are good. Proceed to Test C: ECM COMPRESSOR CONTROL TEST. C: ECM Compressor Control Test

^ If the A/C Compressor Clutch does not engage proceed to Test B: A/C COMPRESSOR CLUTCH TEST. B: A/C Compressor Clutch Test