Manual Air Conditioning

System Outline

1. Heater Blower Motor Operation

- Low speed operation
When the heater control SW is moved to LO position, current flows to TERMINAL LO of the heater control SW to GROUND, activating the HTR relay. This causes the current to flow from the HTR (50A) fuse to TERMINAL 5 of the HTR relay to TERMINAL 3 to TERMINAL 2 of the blower motor to TERMINAL 1 to TERMINAL 1 of the blower resistor to TERMINAL 4 to GROUND, causing the blower motor to rotate at low speed.

- Medium speed operation (Operation at M1, M2)
When the blower SW is moved to M1 position, current flows to TERMINAL LO of the heater control SW to GROUND, turning the HTR relay to switch on. This causes the current to flow from the HTR (50A) fuse to TERMINAL 5 of the HTR relay to TERMINAL 3 to TERMINAL 2 of the blower motor to TERMINAL 1 to TERMINAL 1 of the blower resistor to TERMINAL 2 to TERMINAL (B) 5 of the heater control SW to GROUND. At this time, the blower resistance of the blower resistor is less than at low speed, so the blower motor rotates at medium low speed.

When the blower SW is moved to M2 position, current flows through the motor flows from TERMINAL 1 of the blower resistor to TERMINAL 3 to TERMINAL (B) 6 of the heater control SW to GROUND. At this time, resistance of the blower resistor is less than at M1 position, so the blower motor rotates at medium high speed.

- High speed operation
When the blower SW is moved to HIGH position, current flows to TERMINAL LO of the heater control SW to GROUND, turning the HTR relay to switch on.

This causes the current to flow from the HTR (50A) fuse to TERMINAL 5 of the HTR relay to TERMINAL 3 to TERMINAL 2 of the blower motor to TERMINAL 1 to TERMINAL (B) 7 of the heater control SW to GROUND, causing the blower motor to rotate at high speed.