Compressor Clutch Relay: Testing and Inspection

Air Conditioning Switch And Relay Circuit:

To test the Air Conditioning Relay, located in the engine compartment, proceed as follows:

COMPONENT TEST
1. Remove the A/C relay.
2. Using an ohm meter, check for continuity between terminals 3 and 1.

Continuity: Should exist

3. Apply 12vdc across terminals 3 and 1 of the relay.
4. Using an ohm meter check for continuity between terminals 4 and 5.

Continuity: Should exist

HARNESS TEST
1. Using a volt meter, check for voltage between harness terminal 4 of the A/C relay and ground.

Voltage: System voltage

2. Turn the key to the OFF position and disconnect the ECU connectors.

3. Turn the key, A/C and blower switches to the ON position and check for voltage at harness terminal 22 of the A/C relay.

Voltage: System voltage

4. Turn the key to the OFF position.
5. Using an ohm meter check for continuity between ECU harness terminal 22 and relay harness terminal 1.

Continuity: Should exist

If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, confirm that the repair has corrected the problem.

If the trouble returns, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.