Electrical System

The electrical system consists of these components:
- blower motor
- heater blower motor switch
- A/C-heater function selector switch
- heater blower motor switch resistor with a thermal limiter
- A/C pressure cut-off switch
- A/C cycling switch
- A/C clutch
- Constant Control Relay Module (CCRM)
- Powertrain Control Module (PCM)
- fuses and wiring to complete the circuit

The blower motor is installed in the heater blower motor housing, which is part of the A/C evaporator housing.

The heater blower motor switch:
- is mounted on the integrated control panel.
- with the heater blower motor switch resistor, allows the selection of tour blower motor speeds.

The heater blower motor switch resistor:
- is installed in the A/C evaporator housing.
- contains a thermal limiter which is used as a temperature protecting fuse.

Relays
The manual A/C heater electrical system uses a relay and two pressure-sensitive switches to control system functions. These components are:
- A/C clutch control relay.
- A/C pressure cut-off switch
- A/C cycling switch

A/C Clutch Control Relay
The A/C clutch control relay enables the A/C clutch when commanded to do so by the Powertrain Control Module (PCM). The A/C clutch could be disabled under these conditions:
- engine start-up
- Wide Open Throttle (WOT)
- during low engine idle conditions
- excessively high engine temperatures

The A/C clutch control relay is a normal open relay connected in the A/C clutch circuit. When the relay is energized by the powertrain control module, it enables A/C clutch operation.