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).

GENERAL OPERATION
The ECM will take inputs from the A/C switch on the dash, Engine Coolant Temperature Sensor and the Vehicle Speed Sensor to determine whether the radiator fan should be off, low speed or high speed. Refer to the "DATA TABLES" for specific operational data.

Radiator Fan Operation (A/C Switch OFF):

A/C SWITCH "OFF" DATA TABLE

Radiator Fan Control Operation (A/C Switch ON):

A/C SWITCH "ON" DATA TABLE