Heater Control Power and Ground Circuit Troubleshooting

  1. Check for continuity between the heater control unit 32P connector terminal No. 29 and body ground.
Is there continuity?
YES -
Check for loose wires and poor connections at the heater control unit 32P connector. If connections are good, substitute a known-good heater control unit and recheck. If the symptom/indication goes away, replace the original heater control unit .■
NO -
Check for an open in the wire between the heater control unit and body ground. If the wire is OK, check for poor ground at G503. ■