Express 1/2 Ton Van V8-305 5.0L VIN M SFI (1998)
Control Module HVAC: Description and Operation
A/C System
The blower switch provides a choice of various blower speeds. The blower switch receives power through a fuse in the fuse block when the ignition
switch is "ON." In the low-speed position, the circuit continues through the heater wiring harness to three resistors in the resistor assembly near the
blower motor.
When the blower switch is in a medium-speed position, the circuit continues through the heater wiring harness to the resistor assembly, but it bypasses
one or two of the resistors.
When the blower switch is in the "HI" position, the circuit continues through the heater wiring harness to the resistor assembly, but it bypasses all three
resistors to provide full power to the blower motor.
From the resistor assembly, the circuit goes to the blower motor terminal to operate the blower motor.
