Test A - Isolation Test

Isolation Test - Voltage Test:

1. Remove the connector from the Pressure Cycling Switch and measure the voltage to ground at the LT GRN (66) wire of the connector. Turn the Ignition Switch to RUN but do not start the engine.
^ If voltage is correct, proceed to step 2.
^ If voltage is incorrect, proceed to A/C Compressor Controls Test.
2. With the connector still removed from the Pressure Cycling Switch, connect a fused jumper between the two terminals of the connector. Note Compressor Clutch action.

Isolation Test - Jumper Test:

^ If the A/C Compressor Clutch engages (loud click), check the refrigerant charge according to the specified procedure. If the refrigerant charge is OK, replace the Pressure Cycling Switch.
^ If the A/C Compressor Clutch does not engage, proceed to A/C Compressor Clutch Test. Test D - A/C Compressor Clutch Test