Control Module HVAC: Description and Operation

A/C HEATER CONTROL MODULE




The manual temperature control HVAC system uses a combination of electrical, and vacuum controls. These controls provide the vehicle operator with a number of setting options to help control the climate and comfort within the vehicle. Refer to the owner's manual in the vehicle glove box for more information on the suggested operation and use of these controls.

Both A/C heater control module panels are located on the instrument panel inboard of the steering column and above the radio. The A/C heater control panel contains two rotary-type temperature control knobs (2 and 5), a rotary-type mode control switch knob (1), a rotary-type blower motor speed switch knob (6) and an air conditioning compressor push button switch (3).




Dual zone temperature control provides a side-to-side variation in comfort temperatures to exceed the needs of either front seat occupant.

The A/C Heater Control Module panels are serviced only as complete units and cannot be repaired. If faulty or damaged, the entire A/C Heater Control Module must be replaced.

The A/C Heater Control Module makes it possible to make adjustments coming from the driver such as:
- "Temperature" by setting the temperature thumb wheels. (2 and 5)
- "Air quantity" by adjusting the blower switch setting. (6)
- "Air distribution" by setting the air distribution switch. (1)
- "Recirculating air" by pressing the recirculating air push-button. (4)
- Activating the residual engine heat utilization system with the ignition switched off by pressing the REST button. (4)
- Switching off the A/C by pressing the EC button (3).

The A/C Heater Control Module integrated in the push-button control module looks after all system regulation and control functions, such as:
- Automatic switchover from fresh air to recirculated air mode.
- Electrical control of the A/C compressor.
- Control of the electric fan for the engine/air conditioning system.