Isolation Test

Trouble Isolation Test:

NOTE: This test is to be performed with the Ignition Switch in RUN (engine not running), and the Function Selector in NORM.

Remove the connector from the A/C Cut-Out Relay and measure the voltage to ground at the following terminals of the connector. Turn the Ignition Switch to RUN but do not start the engine.

1. If all voltages are correct, proceed to A/C Compressor Clutch Tests.
2. If Battery voltage is not present at terminal A, remove the connector from the Power Steering Pressure Switch and connect a fused jumper between the two terminals of the connector.

^ If Battery voltage is now present at terminal A, replace the Power Steering Pressure Switch.
^ If Battery voltage is not present, check the ERLS Fuse.
^ If the fuse is good, check the PPL wire (901) and PNK/BLK and PNK wires (639) for an open.

3. If Battery voltage is not at terminal B, proceed to A/C Compressor Control Test. A/C Compressor Clutch Test