Air Conditioning Switch: Description and Operation

Radiator Fan Control Inputs And Outputs:

PURPOSE

The A/C input signal(s) allow the Engine Control Module (ECM) to control the radiator fan relay(s).

OPERATION
The ECM will take inputs from the A/C switch on the dash, the Thermal Control Amplifier and the A/C Triple Pressure Switch to determine whether the radiator fan should be off, low speed or high speed.