Front Air Conditioning

1. HEATER BLOWER MOTOR OPERATION
Current is applied at all times through the HTR fuse to TERMINAL 1 of the front heater relay.

When the ignition SW is turned ON, the current flows through HEATER fuse to TERMINAL 3 of the front heater relay to TERMINAL 5 to TERMINAL 3 of the blower SW.

* Low speed operation
When the blower SW is moved to LO position, the current flows to TERMINAL 3 of the blower SW to TERMINAL 1 to GROUND, causing the front heater relay to turn ON. This causes the current to flow from the HTR fuse to TERMINAL 1 of the front heater relay to TERMINAL 2 to TERMINAL 2 of the blower motor to TERMINAL 1 to TERMINAL 2 of the blower resistor to TERMINAL 3 to GROUND, rotating the blower motor at low speed.

* Medium speed operation (Operation at M1, M2)
When the blower SW is moved to M1 position, the current flows to TERMINAL 3 of the blower SW to TERMINAL 1 to GROUND, causing the front heater relay to turn ON. This causes the current flows from the HTR fuse to TERMINAL 1 of the front heater relay to TERMINAL 2 to TERMINAL 2 of the blower motor to TERMINAL 1 to TERMINAL 2 of the blower resistor to TERMINAL 1 to TERMINAL 4 of the blower SW to TERMINAL 1 to GROUND. At this time, the blower resistance of the blower resistor is smaller than at low speed, so the blower motor rotates at medium low speed.

When the blower SW is moved to M2 position, the current through the motor flows from TERMINAL 2 of the blower resistor to TERMINAL 5 to TERMINAL 8 of the blower SW to TERMINAL 1 to GROUND. At this time, resistance of the blower resistor is smaller than at M1 position, so the blower motor rotates at medium high speed.

* High speed operation
When the blower SW is moved to HI position, the current flows to TERMINAL 3 of the blower SW to TERMINAL 1 to GROUND, causing the front heater relay to turn ON.

This causes the current to flow from the HTR fuse to TERMINAL 1 of the front heater relay to TERMINAL 2 to TERMINAL 2 of the blower motor to TERMINAL 1 to TERMINAL 5 of the blower SW to TERMINAL 1 to GROUND, rotating the blower motor at high speed.

2. AIR CONDITIONING OPERATION
When the blower SW is set ON, the current from the HEATER fuse flows to TERMINAL 1 of the A/C dual pressure SW to TERMINAL 4 to TERMINAL 3 of the A/C amplifier. The engine RPM signal from the Engine Control Module, the evaporator temp. signal from the A/C thermistor and the lock signal from the lock sensor are all supplied to the A/C amplifier.
When the A/C SW is turned ON, a signal is sent to the A/C amplifier. The current flows from the HEATER fuse to FAN NO.3 relay (Coil side) to TERMINAL 13 of the A/C amplifier to TERMINAL 6 to GROUND, turning the FAN NO.3 relay ON.