Blower Resistor Circuit Board
Remove blower resistor wiper arm assembly (see above and note CAUTIONS on loose ball bearings) . Take out three blower resistor circuit board retaining screws and two retaining screws in electrical connector body, then lift out blower resistor circuit board, electrical connector, and wiring as an assembly. Install this assembly by reversing removal procedure and adjust feedback potentiometer (see ADJUSTMENT in individual data for each car model) .
General Motors Automatic Temperature Control Testers are available and necessary to test and adjust ATC systems, Instructions for connecting and using the Testers are on cards attached to each Tester. The following table lists year car models and the correct Tester for each system.
Buick
| Model Year | Tester No. |
|---|---|
| 1969-70 | None |
| 1971-72 | J-23678 |
Cadillac
| 1969-70 | J-22368-01 or J-21512 | |
| 1971-72 (Front Unit) | J-23678 | |
| (Rear Unit) | J.-22368-01 or J-21512 | |
Chevrolet & Oldsmobile
| 1969-70 | J-22368 |
| 1971-72 | J-23678 |
Pontiac
| 1969 (All Models) | J-22684-02 | |
| 1970 (Except Grand Prix) | J-22368 | |
| (Grand Prix) | J-22684-01 or J-22684-02 | |
| 1971-72 (Except Grand Prix) | J-23678 | |
| (Grand Prix) | J-22684-01 or J-22684-02 | |