General Information

The purpose of the heater is to supply heat to the interior of the vehicle. The vehicle operator can determine the level of heat by sliding the temperature control, located on the HVAC control module, to any setting. The temperature control can change the vehicle's air temperature regardless of the HVAC mode setting, heater or A/C.

The I/P fuse block provides power to the left air temperature actuator through the ignition 3 voltage circuit. Power and ground are provided to the HVAC control module by the ignition 3 voltage and ground circuits.

When a desired temperature setting is selected, a variable resistor is used to determine the air temperature door control signals value. A resistor inside the HVAC control module provides a varying ground. This changes the 12-volt signal coming into the actuator and varies the voltage so the actuator is moved into the proper position. The motor opens the left air temperature actuator to a position to divert sufficient air past the heater core to achieve the desired vehicle temperature. Ground is provided by the ground circuit and HVAC control module.