C 3500 Truck 2WD V8-6.0L VIN U (2001)
Air Door Actuator / Motor: Description and Operation
HVAC Systems - Manual
The vehicle operator can determine the temperature of the A/C air by using the temperature control. A 5-volt reference signal is sent out over the 5-volt
reference circuit to the air temperature actuator. When a desired temperature setting is selected, a variable resistor is used to determine the air
temperature door position signals value. That varied 5-volt reference signal is sent back to the HVAC module software inside the HVAC control module
on the air temperature door position sensor signal circuit. The HVAC module uses this reference voltage to determine the air temperature actuator
position through the air temperature door position signal circuit. The motor opens the air mixture door to a position to divert sufficient air past the
evaporator to achieve the desired vehicle temperature. Warm heater air is mixed with cool A/C air at the air mixture door. When the coldest temperature
setting is selected, a 5-volt reference signal is sent and no warm heater air is mixed with the cool A/C air.
