Power headrests won't move

General E28 FAQs.
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C.R. Krieger
Posts: 14507
Joined: Feb 12, 2006 12:00 PM
Location: Halfway up the left side of Lake Michigan
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Post by C.R. Krieger »

Problem: My power headrest(s) won't move, even though I can hear the motor running when I push the buttons.

Solution: Fix the cable drive(s).

Difficulty: Different levels of simple, depending on the solution you choose. What happens is that the cable housing around the drive cable stretches over the years and the drive cable isn't quite long enough to reach the drive gear. You can address this in a very simple (some would say 'shortsighted') manner or you can spend more time fixing it 'right'.

For either procedure, you need to remove the seatback cover, which, like this job, is lots easier than it looks. Run the seatback as far forward as possible. This exposes the small screws on the bottom that hold the seatback cover in place (They point nearly vertically downward; easier to reach than to see.). Remove them, pull the cover out slightly, and then lift up on it, as it's held at the top by two spring clips. [This is for 535is sport seats; if the procedure on non-sport seats is different, PM or email me and I'll correct it.]

Inside, on the outboard side of the seat, you'll find the headrest motor (small canister - if you're not sure, just press the button and listen for it.) held in by 10mm nuts. Remove these carefully, as they seem to have a propensity for falling down into the inaccessible seat innards. Having one of those collapsible 'antenna' magnets handy isn't a bad idea. Don't ask how I know. :@ Unplug the electrical connector.

Turn the motor with the cable drive upright and disconnect it (knurled nut). Now you have a choice. You can 'Do Da Right T'ing' by actually cutting the cable housing shorter by up to 3/16" or you can do the simple expedient: cut about 3/16" (OK; 5 mm if you're totally metrified) of something like a wire coat hanger or a hunk of #12 copper wire and drop it into the hole on the motor where the drive cable seats. This pushes the cable out enough to engage the gear drive at the other end. As for me, I have a lifetime supply of 'simple expedient' material in a single coat hanger waiting for future failures, so if you want to cut the cable housing, it's up to you to figure out how. It can't be that hard, now that you know what the problem is ...
Last edited by C.R. Krieger on Mar 11, 2006 11:49 AM, edited 1 time in total.
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