Brake light circuit

[Steinkek]

I have read lots of posts on the brake light circuit and how to replace it. But I have a diffrent question. What exactly does the brake light circuit do? Is it a problem if its not replaced right away? Another thing is, the check controls light that tells me its out only comes on about half the time im driving. What should i do?

[iantosca]

I recommend you just replace it, I had the same problem. It gets extremely annoying after a little while.

[theogill]

If I undertand it correctly (I'm having the same problem and thinking about getting under the dash soon), there is a brake light switch that is activated when you depress the brake pedal. The actual circuit board is on the backside of the lamp cluster, and sometimes gets oxidization or something, and then the contact between the bulb socket and the circuit is compromised. From the posts I have read it seems that even when you take care to optimize the contact, the code still shows--which then indicates it's that brake light switch under the dash.
Hope thats helpful, it may not be all that accurate--but thats my understanding.
Ted

[Steinkek]

Thanks for the suggestions guys. I think that when i get some money I will just go ahead and take care of it.

[bitcore]

I had this problem... and it TOTALLY SUCKED.

If you have cruise control, then you have the 4 pin brake siwtch, otherwise, you should have the 2 pin brake switch. Do not buy this switch from bavauto. Suck it up and go to the dealership and get OEM. Saving 10$ will result in a *LOUD* brakeswitch. I know this because I bought both. Believe me, it's unbearably loud, even with the bodypanel put back in it's place. It only takes a minute at the dealership vs. waiting a few days for a crappy one to arrive in the mail.

Check all of your bulbs about 3 times over. MAKE ABSULTEY SURE THEY ARN'T BLOWN. If youre unsure, Replace them with a bulb from any autoparts store. They arn't more than 2$ each. Hell, Replace them twice, I had to. :P If they blow often or this dosn't help your problem after youve tried everything, go OEM. The BMW gods may be frowning on your taillight bulb selection.

Polish the contacts on the bulb holders, and the taillight assembly, this can help to some degree or could be the problem.

Make sure all of the connections to the tailight assemblys are secure and the pins in the plugs havn't backed out.

Do the obvious, check fuses, replace any that are blown with the same amperage rating.

[BMWJNKY]

Originally posted by theogill@Aug 28 2004, 06:49 PM
If I undertand it correctly (I'm having the same problem and thinking about getting under the dash soon), there is a brake light switch that is activated when you depress the brake pedal. The actual circuit board is on the backside of the lamp cluster, and sometimes gets oxidization or something, and then the contact between the bulb socket and the circuit is compromised. From the posts I have read it seems that even when you take care to optimize the contact, the code still shows--which then indicates it's that brake light switch under the dash.
Hope thats helpful, it may not be all that accurate--but thats my understanding.
Ted

If it says brake light circuit 99% of the time it is a bad brake light switch, if the check control says brake lamp then it is a bulb problem. I've seen it numerous times at the shop I work at where a coustomer will state that the brake circuit warning in the check control only comes on sometimes, we put in a new siwtch and the problem is fixed.