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Climate Control Power and Ground Circuit Troubleshooting

Climate Control Power and Ground Circuits Troubleshooting

1. Check the No. 16 (30 A) fuse in the under-hood fuse/relay box, and the No. 16 (7.5 A) and No. 18 (7.5 A) fuses in the under-dash fuse/relay box.

Are the fuses OK?

YES - Go to step 2.

NO - Replace the fuse(s), and recheck.

2. Disconnect climate control unit connector A (12P).
3. Turn the ignition switch ON (II).




4. Measure the voltage between the No. 2 terminal of climate control unit connector A (12P) and body ground.

Is there battery voltage?

YES - Go to step 5.

NO - Repair open in the wire between the No. 16 fuse in the under-dash fuse/relay box and the climate control unit.

5. Turn the ignition switch OFF.




6. Measure the voltage between the No. 3 terminal of climate control unit connector A (12P) and body ground.

Is there battery voltage?

YES - Go to step 7.

NO - Repair open in the wire between the No. 18 fuse in the under-dash fuse/relay box and the climate control unit.




7. Check for continuity between the No. 10 terminal of climate control unit connector A (12P) and body ground.

Is there continuity?

YES - Check for loose wires or poor connections at climate control unit connector A (12P). 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.

NO - Check for an open in the wire between the climate control unit and body ground. If the wire is OK, check for poor ground at G404.