A/C Signal: Testing and Inspection

CIS-E III Control Unit Harness Connectors (Pin # Locations):

The relay signals the fuel control unit when the air conditioning is turned on by applying battery voltage to terminal #33 of fuel control unit (parallel circuit with A/C clutch).

1. Disconnect harness connector from fuel control unit.

2. Turn ignition "ON", and check voltage between harness connector terminals #33 and #35 (ground). There should be no voltage present.

2. Turn A/C on. Compressor clutch should energize and voltage at terminal #33 should change to battery voltage (within 1 volt). If not, check the relay, listen for a "click" when A/C is turned on and off. If it "clicks" check for open or grounded circuit between fuel control unit terminal #33 and A/C relay terminal 58.