Problem With 735i Brake Light - BMW Forum

Pro-Hunter · 05-04-2006, 05:54 AM

I have a 1992 735i each time I brake an indication says (Brake LT Circuit) I changed the brake switch under the steering wheel nothing happened, I changed the brake lights, and nothing happened too. And I have no rear window brake light, it’s annoying to have everything working properly and getting each time a fault code.
Any ideas on how to fix this?
Thanx.

LOS · 05-04-2006, 09:21 AM

Check the contact for corrosion. Make sure the bulb makes contact with the housing.
I have also heard the new bulb needs to be same brand as original. It seems like our older cars are a little more spoiled.

LOS

325isBaby · 05-04-2006, 12:42 PM

Agreed, check for burn spots in the light socket and on the contact to the housing (if you are lucky you won't have to replace the lamp assembly) and as LOS said, the bulbs have to be factory (it has to do with the ohm rating in BMW bulbs)

Pro-Hunter · 05-04-2006, 05:01 PM

Thank you guys i'm gonna try to fix this problem and i'll post the result
Thanks anyway.

Dirty_Tool · 05-04-2006, 11:49 PM

if youre in the US a 92 should have a 3rd brake lamp. Did I understand you correctly that you do not have 1?

saltshaker185 · 05-05-2006, 10:51 PM

"you have no rear window brake light" does this mean that you have one and its burnt out? or that you just dont have one in general?

AllGo'n'Show · 05-20-2006, 10:59 AM

LKM/Mustard Relay seem to be your problem there bud...

http://www.e32fixes.com/results.asp?...ow_fix&fixid=2

Is a fix site with some pictures as well, there are many out there.

What happens is the solders on the crowns of the connections in the LKM, crack and break off over a period of time. Resolder them up and make them look liek new, reinstall, and bingo, good to go.

I have done the fix myself, in the dark, at 1am, only took me about 20 minutes, having a nice big magnifing glass helps find the cracked solders, very easy just take your time.