How to Replace the Blower Motor in a 1994 BMW 325

1. Raise the hood and disconnect the negative battery cable with a socket wrench. Locate the firewall cover; this is a rubber housing that rests against the firewall. Use a socket wrench to remove the four bolts that secure the firewall cover to the firewall (the bolts are located along the top of the cover), pull it out of the engine compartment and set it aside.
2. Locate the blower motor housing secured to the firewall -- its location corresponds to the center console in the cabin of the vehicle. Use your fingers to loosen the clips that secure the housing to the firewall and then pull the blower motor out of the housing and remove the wiring from the back of the motor. Attach the wiring to the new blower motor and insert it into the housing.
3. Tighten the clips around the new blower motor, securing it into the blower motor housing. Slide the firewall cover back into the engine compartment and reattach the four firewall cover bolts to secure the cover back onto the firewall.
4. Reconnect the negative battery cable and close the hood. Turn the car on and turn the air-conditioning on to its highest setting for ten minutes to ensure that the new blower motor is functioning properly.