E21 Heater Blower Motor R & R

From: Robert Walthall, robert.walthall@wcom.com To: E21Autos, e21autos@ix.netcom.com

The heater on my 1980 320i quit working. The fan would not work on any setting (1, 2, or 3). When I first bought the car, the fan would work (only on high (3)). When I first turned it on it would squeak a lot. (It reminded me of the wheel in a mouse cage with a very old mouse.) Sometimes it would be working and just stop. A few well placed bangs on the dash would usually get things going again. Then one day it quit working completely. So I decided early Sat. morning to poke around a little and see what I could find. Eventually I did find the heater motor. I cleaned the motor windings, and now it works great (all three speeds!). The Haynes manual gave me a few clues, but it was still a lot of guess work. So I thought I'd post the procedure. Haynes instructions in quotes. Here's what I did:

1. "The heater motor can be removed form the engine side of the bulkhead. First remove the heater cover retaining screws and lift off the cover. Disconnect the negative battery terminal." The heater cover is located directly below the windshield wipers. There is a rear rubber seal for the bonnet that should be removed revealing some of the retaining screws. The retaining screws are 4 phillips head screws (on top), and 6 (8mm) bolts on the bottom and sides. There are 3 or 4 clips attached to the heater cover holding various wiring harnesses. Pull the wiring harnesses from the clips and let them hang for a while. Remove the cover.

2. "Prise off the water deflector shields from each side of the heater, and unscrew the heater upper mounting nuts." There is a 10mm nut anchoring each of the water deflector shields. There are no heater upper mounting nuts to find. A deep socket is required to remove the water deflector shield nuts.

3. "Snap open the 2 impeller cover clips, pull out the plastic retaining studs, and lift off the two covers." Remove the metal clips located on the upper left and right hand corner of each impeller cover (an impeller is a round fan blade similar to the wheel in a mouse cage ( no mice were found), there is one on each side of the motor). The hardest part of this entire project was getting the impeller covers off. At this point there was nothing to keep them from being removed, but it took considerable pulling, pushing prying, trying moments before one of them came off. There is a tongue and grove setup on the top and bottom of each cover. On the end of the tongue there is a plastic bump that keeps it from sliding freely in and out. Theoretically, if one could reach in there with something and push down on the tongue you could pull it right out...good luck.

4."Snap open the heater motor retaining clip, separate the supply lead connectors, and lift the motor away from the casing." There is a spring clip in the center of the heater motor. Unclip it and remove the leads. The motor should come right out. I picked up a can of "Tuner/Control Cleaner & Lubricant" from Radio Shack a few years ago. The cleaner was sprayed on the copper windings of the motor which were previously covered in black gunk. Replace procedure is the opposite of removal.

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