E34 Brake LT Circuit Fault !!HELP!! - United Bimmer Community

**Ashloch** · 03-14-2007, 01:53 AM

I would appreciate any help, if you can provide it.
I own a 525i that gets a "brake LT circuit fault" soon as I depress the brake pedal. The lights, unfortunately don't illuminate, but the brakes work.
The dealer says that it "could be" a K3 relay problem (known to them as a manufacturer's defect) and they want $200 to replace a relay! Thats the equivalent of paying them to replace a fuse!
Can anyone tell me where that relay is located on the car?
Its NOT identified on any fuse/relay panel and the dealership won't give me any further info on its location.
I'm hoping that this collective can assist.
There's a bottle of wine in it for you (if you're old enough to drink).

**c1apton** · 03-14-2007, 05:53 AM

It's the brake-light switch (just above your brake pedal) it takes about 10 minutes to change. The part itself sells for about $20 - but since it's a safety part - tell them it's part of an "open campaign" and it also supposed to be replaced for FREE by authorized BMW dealers.

**Ashloch** · 03-31-2007, 02:17 PM

Elwood,
The weather in the UK has finally cleared enough for me to take a look, and, at first, I was thrilled to hear that it was something simple. So armed with my tools I stripped the panels away from the pedals. I was shocked to find no switch near the brake pedal. Just a system of braces and levers that attach to a long rod which dissappears behind the center carpeting of the dashboard. Is the elusive switch behind (smack in the middle of the dash behind the fan motor, ductwork and all the wiring) all of this stuff? Once again I am stumped by this car.
I will, however, use your advice and try to get the dealer to correct the problem on the attitude of safety. But, English garages are not built on favors. This one has the letter which states the liability with the recall expired in 1998.

**Dudesky** · 03-31-2007, 02:21 PM

Elwood

**c1apton** · 03-31-2007, 03:39 PM

Item # 6 is the part you're after

**Ashloch** · 04-02-2007, 01:00 AM

C1apton,
The diagram is FABULOUS! The only problem is that the view is not the configuration I have. The bracket that holds the switch is there but the hole (for the switch) is empty.
Its an automatic (I know!) so there is no clutch pedal either.
If you can imagine, there is a linkage attached to a long rod which runs behind the bracket and disappears (to the left of the view you provided) behind the center of the dash assembly, carpet, etc. Not sure where that is linked to. Can you help? You've been invaluable so far and I thank you for being so patient.
~Ashloch

**c1apton** · 04-02-2007, 03:09 AM

The long rod goes through the firewall into the backside of the master-brake cylinder. If you dig around above the brake pedal you'll find the switch. Sometimes it's easier to locate with lower dash panel removed -

**Ashloch** · 04-06-2007, 12:29 AM

C1apton! Thanks much!
I found the elusive switch. I had to follow the linkage to the passenger side of the car! Low and behold the switch was exactly where you said it would be –behind the master cylinder on the inside of the firewall. Being British spec it’s designed a little differently. Why, I just don’t have a clue. The same bracket for the switch is right above the brake pedal. Why build another bracket that puts it somewhere else???
I’m headed to the junk yard this weekend to pinch one off of another E34. The dealer would take 2 weeks to get the part. Will post the results. Thanks for your assistance! If you’re old enough to drink the bottle of wine is still on the table. Just let me know your preference (red or white). There are some gorgeous reds right across the Channel!

**Ashloch** · 04-12-2007, 12:32 AM

C1apton,
I have brake lights! The switch I removed from the junkyard works like a champ! It was much easier than I thought to get to it. All I had to do was remove the glove box, and a small cover panel.
Seems the UK spec Bimmers use the same firewall, but the switch is on the passenger side (right where you said it would be).
The bottle of wine is availabe if you wish. Just send me a shout.
Thanks again for your assistance!