Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Function Selector Knob
The function selector actuates an 8-port A/C vacuum control switch which controls vacuum control motors at floor, defrost/panel, defrost and outside/recirculation air doors. The function selector also controls on-off operation of the heater blower motor switch and activates the circuit for the A/C clutch circuit in the A/C position.
In following modes, compressor operation is dependent on the A/C cycling switch: A/C (MAX or NORM), FLOOR/DEFROST and DEFROST. See Figure. Cut-out pressure is about 23 psi (1.6 kg/cm2 ). Cut-in pressure is about 46 psi (3.2 kg/cm2 ).
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.