Heater Control Power and Ground Circuit Troubleshooting
Heater Control Power and Ground Circuit Troubleshooting1. 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.
2. Disconnect the heater control panel 30P connector.
3. Turn the ignition switch ON (II).
4. Measure the voltage between the No. 3 terminal of the heater control panel 30P connector and body ground.
Is there battery voltage?
YES - Go to step 5.
NO - Repair 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 OFF.
6. Check for continuity between the No. 4 terminal of the heater control panel 30P connector 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.
NO - Check for an open in the wire between the heater control panel and body ground. If the wire is OK, check for poor ground at G501.