Fan Speed Control

FAN SPEED CONTROL


318ti










Fan speed is controlled using a four-position switch and a resistor pack to vary blower motor voltage. The resistor pack is mounted on the heater case in the air stream for cooling purposes.

The resistor pack is accessible from the engine compartment with the microfilter removed. To access the microfilters, remove the air inlet grille at the center of the cowl. Unscrew the air inlet bulkhead panel and plastic cover. Pull the bulkhead panel from engine compartment and remove the exposed microfilters.

The fan switch is the master controller for the system. In the 0 position, the A/C compressor is switched off, the recirc flaps are opened, and the fresh air flaps are closed.

In fan speeds 1, 2 and 3, the blower motor's speed is cut back with the resistor pack. In speed 4, the blower motor receives full battery voltage.

The recirc LED over the button will remain On when the fan switch is Off to indicate the recirc mode. There is no possibility of fresh air in the cabin with the fan switch Off.

The fresh air/recirc flaps are controlled with one motor. The fresh air flaps are open until the recirc button is pressed or the fan switch is switched Off.

Z3













The resistor pack in the Z3 IHKS is located on the blower motor. It's accessible from the engine compartment. Remove the blower motor cover. Unclip the resistor pack from the blower motor and pull outward.

On the Z3, the fan switch controls only the fan speed. It has no influence on the recirculating air function as it does on the 318ti. The fresh air flaps remain open when the switch is in the 0 position. If the recirculating air or "snowflake" button is pressed with the fan switch in the 0 position, the fan will automatically run at very slow speed.