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Subject: OBC light repair Author: DavidC (moderator) : member since December, 2003 : 11909 posts Posted on: 2004-04-17 05:34:46

I figured out the answer.

The OBC (onboard computer) in my '86 735i works, but the buttons weren't illuminating. The ETK shows the lightbar as the only light source, but there is also a small 1.2W/12V bulb in a twist socket in the back of the unit.


The front of the OBC, removed from the dash.


The 1.2W/12V socket and bulb. The BMW part # 62 11 1 368 299 and the cost is $1.65 at your local dealer. Gently use a pair of pliers to rotate the socket and lift it out of the OBC.


FYI, in case you haven't seen it before, the lightbar is located on the right side of the OBC. The lightbar illuminates the digital display. If your display isn't working, shine a flashlight at it in the dark. If you can see letters/numbers, your OBC is fine -- you just need a new lightbar.


Use a pair of pliers, with a gentle touch, to grasp the end of the light bar and pull it out sideways.


The lightbar removed from the OBC. It's really just two bulbs on a circuit board. Oddly enough, my local dealer (United BMW in Atlanta) stocks them. Evidently they're also used in several other models, including the e24 and e28. They're priced at $28, before CCA discount.

David Cecil
'97 740iL, 119k miles
'86 735i, 91k miles
'77 320i, 140k miles

www.e38.org has links for everything about your BMW 7-series automobile

• Are the buttons on the OBC supposed to be illuminated? - DavidC 2004-04-16 18:10:07 (742 views)
  • OBC light repair (pic) (url) - DavidC 2004-04-17 05:34:46 (8525 views)
    • OBC1 is a little different. It has a small lightbulb that twists in the back. (nt) - Jeff '84 733i 5-Speed 2004-04-17 15:31:26 (818 views)