DeVille V8-4.6L VIN Y (1998)
Control Module HVAC: Description and Operation
Blower Controls
For every given program number and climate control panel setting, the heater and A/C programmer has a calculated blower speed.
The console rear blower speed is controlled manually by a direct power feed. The variable speed is controlled by a resistor which varies the voltage to
the blower motor at each setting. The heater and A/C programmer monitors the feedback for diagnosis.