Electric Cooling Fan

Electric Cooling Fan:

NOTE: The electric cooling fan is only equipped in standard transmission vehicles. The automatic transmission vehicles are equipped with the familiar belt driven, viscous clutch cooling fan.

The operation of the cooling fan on the roadster is similar in operation to the 318ti with M1.7.2. The fan serves a dual function of engine cooling and auxiliary fan operation for the air conditioner.

The fan operates in two stages through a temperature switch, with two switching points of 80 °C and 88 °C.

To prevent idle speed fluctuation caused by the load of the fan motor against the alternator, the DME has total control over the stage I fan speed. The signal from the 80° switch is an input to the DME. When the switch closes, the DME sets up the idle speed controller and adjusts the timing before the stage I relay closes.

Stage 2 relay is controlled by the 88° switch and the pressure switch.