Thermo Control Amp. Check

POWER SUPPLY CIRCUIT CHECK
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.








GROUND CIRCUIT CHECK
Check body ground circuit for thermo control amp. with ignition switch ON, air conditioner switch ON and fan switch ON.

1. Disconnect thermo control amp. harness connector.
2. Connect ohmmeter from harness side.
3. Check for continuity between terminal 2 and body ground.

If the ground circuit is NG, check the following.
- A/C switch
- Fan switch
- Harness for open or short between thermo control amp. and A/C switch
- Harness for open or short between A/C switch and fan switch
- Fan switch ground circuit.