A/C Heater

A/C-HEATER

With the Ignition Switch in the "RUN" position, the contacts of the Ignition Relay close allowing current to flow from the 60A BTN fuse of the Main Fuse Panel, through the 30A HEATER circuit breaker to the Blower Motor, and through the in-line 15A COOLER fuse to the WAC Relay. Current also flows through the Ignition Switch and 20A COOLING FAN fuse to the A/C Control Module, and through the 15A AIR COND fuse to the A/C Switch, the Condenser Fan Motor, the coil of the Condenser Fan Relay and the coil of the WAC Relay. With the Blower Motor Control Switch in any position other than "OFF", proper conditions are met to close the Refrigerant Pressure Switch and the A/C Switch is engaged, the PCM supplies a ground path which energizes the WAC Relay. This allows current to flow through the closed contacts of the WAC Relay to engage the belt driven compressor pulley causing refrigerant to flow. During wide open throttle conditions, the PCM de-energizes the WAC Relay which disengages the compressor clutch.

BLOWER MOTOR CIRCUIT

When the Ignition Switch is in the "START" or "RUN" position and the Blower Motor Control Switch is in any position other than "OFF", current flows from the 60A BTN fuse, through the closed contacts of the Ignition Relay, the 30A HEATER circuit breaker, the Blower Motor, Blower Motor Resistor and the Blower Motor Control Switch to ground. In Blower Motor Control Switch position I, three resistors are in the circuit and the Blower Motor runs at low speed. In position II two resistors are in the circuit and the Blower Motor runs at medium low speed. In position III, one resistor is in the circuit and the Blower Motor runs at medium high speed. In position IV, no resistors are in the circuit and the Blower Motor runs at high speed.