Seat warmer bulbs - fix

[scott 4991]

My passenger heated seat bulb(s) were not working - but the seat warmer worked fine, high and low. I took the switch out, unplugs from the bottom of the switch, and took the switch apart - what an interesting design. There are conductive ball bearings making contact with a circuit board by springs - careful you don't lose these. I am assuming the radio Radio Shack bulbs will work here also, at least that's what I plan to try. Once the switch is out of the housing, you'll see on POST that is pressed into the top circuit board, but it can rotate around this, with a bit of lifting and rotation force. The top board is shown rotated in the picture (attached). I will now replace the lights, re-assemble and try it - but need to get bulbs at R/S tomorrow. This will clean up real nice. Hope this works. (edit) - there are 3 more bearings under the springs that did not come out as grease holding them in place. I will remove and clean)

sc

[Russell]

cool! -- Now do search for various bulb sources. MCM bulbs are much cheaper than radio shack. The archives have some bulb sizes and sources. For example, there are recomendations by others such as use -- MCM T-1 bulb 12V 50 mA with wire terminals is a small clear bulb that fits most other BMW swiitches. Costs about 25-30 cents each. Coat bulbs with Tamiya X-26 clear orange to match rest of lighting. Stock up for when other bulbs burn out.

[RichG]

There are conductive ball bearings making contact with a circuit board by springs

My lights seem to work sometimes and sometimes they don't. Can you tell if I take apart the switch and clean the dumbbell-looking bars if that might help the lights stay on?

The heat part seems to work ok, just the lights have problems.

Thanks

[scott 4991]

Rich, as far as I can tell, any of the ball bearings may cause your problem. Frankly, after doing this, I'm not sure I would do it again. It's a pain getting the bearings back in. But I have not priced the switch yet, so maybe worth the time.

- I recalled I had 2 good Radio bulbs left from when I recently had 1 radio bulb bad and I replaced all 3 with the Radio Shack bulbs - which are dimmer, but work fine. Last night I put the two radio bulbs in this warmer switch - AND FOUND OUT when I took the switch apart, there is one ball bearing that fell out - THIS BEARING KEEPS THE ROCKER SWITCH IN THE CENTER POSITION - "CLICK" IN CENTER POSITION into an indent in the switch - now I need to look around on my driveway to see if I can find it! Bummer. I'm not sure what size it is, but think it's around 2x the size of a BB (as in a BB-Gun). While this does not prevent testing of the switch, the switch now rocks back and forth very easy and would easily get pushed into the 'on' position at any time.

IF YOU TAKE THIS SWITCH APART, look for this bearing immediately, as it will fall out. Shown on the attached picture.

If anyone had a seat warmer that did not work, I'd be interested in your switch!

sc

[Russell]

contact cleaning spray may help. It sure does on the center window switches and radio volume. Just spray around edge of the switch and work back and forth. If not remove switch from car (without takeing it apart) and spray from other angles and work it around. Might work?

Even so, it may be best to just replace the switch. Mine works fine. I think my PO did know it was even there :)

[shogun]

Just a short note:
there are old and new design switches.
Inside they look completely different and they are not interchangeable. New ones have electronic circuit inside.

[RichG]

IF YOU TAKE THIS SWITCH APART, look for this bearing immediately, as it will fall out.

Will do.

I had the fun of taking apart the main seat adjustment switch without knowing what was inside and was surprised at all the springs and bars. Lost a spring somewhere, but had something similar that could take its place. I had to take the switch apart because it stopped working after it blew a fuse. I think the bars had worn and just by taking the switch apart and repositioning the bars (and cleaning them) fixed it.

Also, mine is a 90 525i so the switches are probably the same (as Shogun mentioned in another post about different switches).

Thanks.

[Bill R.]

seat switch for any that aren't familiar with its workings.
(http://www.lehrmangroup.com/rickard/seatswitch.html)




Will do.

I had the fun of taking apart the main seat adjustment switch without knowing what was inside and was surprised at all the springs and bars. Lost a spring somewhere, but had something similar that could take its place. I had to take the switch apart because it stopped working after it blew a fuse. I think the bars had worn and just by taking the switch apart and repositioning the bars (and cleaning them) fixed it.

Also, mine is a 90 525i so the switches are probably the same (as Shogun mentioned in another post about different switches).

Thanks.

[shogun]

it's always on my favorite list, Bill ;-)