Heater Control Power and Ground Circuits Troubleshooting
Heater Control Power and Ground Circuits Troubleshooting1. 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 the heater control panel connector A (12P).
3. Turn the ignition switch ON (II).
4. Measure the voltage between the No.2 terminal of the heater control panel 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 heater control panel.
5. Turn the ignition switch OFF.
6. Measure the voltage between the No.3 terminal of the heater control panel 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 heater control panel.
7. Check for continuity between the No.10 terminal of the heater control panel connector A (12P) and body ground.
Is there continuity?
YES - Check for loose wires or poor connections at the heater control panel connector A (12P). 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 G404.