Fast Car

1. Disconnect the cable that goes to the negative terminal on the battery. Locate the blower motor. This will almost always be in the dashboard or the firewall area of the car, but the location depends on the model of the car. On some cars, like the Audi A4 for instance, the blower is located behind the glove box, so the glove box must be removed. On other models, the BMW E46 3 Series for example, the blower motor is located just under the windshield and is accessed from the rearward part of the engine bay.
2. Remove any parts that restrict access to the blower. This may be the center console, the glove box or the housing that contains the cabin air filter, often located in the engine bay. Consult a workshop manual for your specific car for detailed instructions on what needs to be removed to access the blower motor.
3. Remove the screws or bolts that hold the blower motor in place. Use a socket and ratchet for bolts or a screwdriver for screws. Disconnect the electrical connections from the blower motor. These are frequently extremely difficult to access, so patience is the key. Once the connections for the blower are disconnected and the blower is unbolted, remove it from the car.
4. Install the new blower in the opposite order that the old blower was removed. Connect the wiring harness or wires to the new blower. Reinstall any parts that were removed to access the blower motor. Turn the car on to make sure that the new blower motor is working.

1. Drive the 325is to your garage or a parking lot. Turn the fan on and feel for any air coming out the vents. If there is no air, then the blower motor needs to be replaced. Put the 325is into Park, then engage the parking brake so there is no danger of gear slippage during the repair. Make sure you have room to maneuver around the front of the BMW for the removal process. Turn the BMW off and open the hood and trunk.
2. Go into the trunk of the BMW and disconnect the negative battery cable from the cars battery. The battery is located in the trunk of the 325is for better weight allocation. Go around to the front of the 325is and prop the hood up with the hood prop stick. The blower motor assembly will be mounted with six screws against the rear firewall. Remove the screws with a Phillips-head screwdriver and pull the blow motor assembly off the firewall.
3. Press the pressure clips on either side of the motor and pull the motor from the blower assembly. If the blower motor has burnt out, then there will be a smell of ozone in the air. If the fan has broken, then some of the blades will be snapped off. In either case the blower needs to be replaced. Disconnect the power wire from the rear of the motor and then connect the power wire to a new blower motor.
4. Slide the blower motor into the blower assembly until you hear the clips click. Then screw the assembly back on the firewall. Tighten all the screws down by hand, as high-torque power drivers could crack the assembly. Close the hood and then go around to the trunk to reconnect the negative battery cable. Close the trunk and then turn the BMW 325is on. Turn the fan up and feel for any air. If there is no air flowing, then the power cord was not plugged in flush. Take the blower motor out and reseat the power cord.