Climate Control Power and Ground Circuit Troubleshooting

1.Check the No. 10 (7.5A) fuse in the under-dash fuse/relay box.

Is the fuse OK?


YES - Go to 2.


NO - Replace the fuse, and recheck.n


2.Disconnect climate control unit 28P connector.

3.Turn the ignition switch ON (II).

4.Measure the voltage between the No. 3 terminal of climate control unit 28P connector and body ground.

 

Is there battery voltage?


YES - Go to 5.


NO - Repair open in the wire between the No. 10 fuse in the under-dash fuse/relay box and the climate control unit.n


5.Turn the ignition switch OFF.

6.Check for continuity between the No. 5 terminal of climate control unit 28P connector and body ground.

 

Is there continuity?


YES - Check for loose wires or poor connections at climate control unit 28P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original  climate control unit.n


NO - Check for an open in the wires between the climate control unit and body ground. If the wire is OK, check for poor ground at G402.n