Heater Control Power And Ground Circuit Troubleshooting

Heater Control Power and Ground Circuit Troubleshooting

1. Check the No. 14 (10 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES -

Go to step 2.

NO -

Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 14 (10 A) fuse circuit.�

2. Disconnect the heater control panel 30P connector.

3. Turn the ignition switch to ON (II).

4. Measure the voltage between heater control panel 30P connector terminal No. 3 and body ground.





Is there battery voltage?

YES -

Go to step 5.

NO -

Repair an open in the wire between the No. 14 (10 A) fuse in the under-dash fuse/relay box and the heater control panel.�

5. Turn the ignition switch to LOCK (0).

6. Check for continuity between heater control panel 30P connector No. 4 and body ground.





Is there continuity?

YES -

Check for loose wires or poor connections at the heater control panel 30P connector. If the connections are good, substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel Service and Repair.�

NO -

Check for an open in the wire between the heater control panel and body ground. If the wire is OK, check for poor body ground at G501; '07-08 models, '09-11 models.�