Operation CHARM: Car repair manuals for everyone.

A/C Control Power and Ground Circuit Troubleshooting

A/C Control Power and Ground Circuit Troubleshooting

1. Check the No. 30 (10 A) fuse in the driver's under-dash fuse/relay box.

Is the fuse OK?

YES - Go to step 2.

NO - Replace the fuse, and recheck.

2. Disconnect A/C control panel connector A (22P).
3. Turn the ignition switch ON (II).




4. Measure the voltage between the No. 11 terminal of A/C control panel connector A (22P) and body ground.

Is there battery voltage?

YES - Go to step 5.

NO - Repair open in the wire between the No. 30 (10 A) fuse in the driver's under-dash fuse/relay box and the A/C control panel.

5. Turn the ignition switch OFF.




6. Check for continuity between the No. 1 terminal of A/C control panel connector A (22P) and body ground.

Is there continuity?

YES - Go to step 7.

NO - Check for an open in the wire between the A/C control panel and body ground. If the wire is OK, check for poor ground at G504.

7. Disconnect the rear A/C control panel 5P connector.
8. Turn the ignition switch ON (II).




9. Measure the voltage between the No. 3 terminal of rear A/C control panel 5P connector and body ground.

Is there battery voltage?

YES - Go to step 10.

NO - Repair open in the wire between the No. 30 (10 A) fuse in the driver's under-dash fuse/relay box and the rear A/C control panel.

10. Turn the ignition switch OFF.




11. Check for continuity between the No. 1 terminal of the rear A/C control panel 5P connector and body ground.

Is there continuity?

YES - Go to step 12.

NO - Check for an open in the BLK wire between the rear A/C control panel and body ground. If the wire is OK, check for poor ground at G601.

12. Disconnect A/C control panel connector B (14P).




13. Check for continuity between the No. 4 terminal of A/C control panel connector B (14P) and the No. 2 terminal of rear A/C control panel 5P connector.

Is there continuity?

YES - Go to step 14.

NO - Repair open in the wire between the A/C control panel and rear A/C control panel.




14. Check for continuity between the No. 2 terminal of rear A/C control panel 5P connector and body ground.

Is there continuity?

YES - Repair short to body ground in the wire between the A/C control panel and the rear A/C control panel.

NO - Check for loose wires or poor connections at A/C control panel connector A (22P), B (14P) and rear A/C control panel 5P connector. If the connections are good, substitute a known-good A/C control panel, and recheck. If the symptom/indication is still present, substitute a known-good A/C control panel, and recheck.