Riviera V6-231 3.8L VIN C SFI (1989)
Radiator Cooling Fan Motor: Description and Operation
The coolant fans on these models consists of a fan located behind the radiator, and a fan mounted in front of the radiator.
The rear fan operates on two speeds, while the front fan operates only on high speed. Both fans are activated any time the coolant fans are in the high
speed mode.
The fans will be activated by the ECM, when the engine coolant temperature sensor or the A/C high pressure sensor reach calibration points.