Trouble Diagnosis Procedures

Check power supply circuit for thermo control amp. with ignition switch ON.
1. Disconnect thermo control amp. harness connector.
2. Connect voltmeter from harness side.
3. Measure voltage across terminal 1 and body ground.







Turn ignition, A/C and fan switches ON. Check body ground circuit for thermo control amp.
1. Disconnect thermo control amp. harness connector.
2. Connect ohmmeter from harness side.
3. Check for continuity between terminal 2 and body ground.