Hello to all.

I checked the Faq, but did not find what I was looking for.

The brake lights on my 1990 740 sedan do not work. The top bulbs light
up when the head lights are turned on, the fuse is fine, I even put in a new one. Any help would be appreciated. I hate going into a three day weekend
with only one vehicle. I will not drive a car without brake lights.

Thank you.

I noticed that both tail lights have a ground wire screwed from the trunk area
and soldered to the tail light. One was broken at the solder area.

I held it with my hand and put it back into position and had someone try the
brakes, but the brakes lights would not light up, but the lights work when the
headlights are turned on. I think the problem is staring me in the face, but
why would some bulbs work and some not ?


Tip

Tom,
Holding a ground wire does not make for a good ground. Resolder the grund wire to the proper place. If the brake lights still don't work, you need to check two places - the switch at the brake pedal and the little red box above the fuses. If you don't want to look at it then wait for Tuesday and go to your local dealer.

Klaus
--
95 850, 88 245

One of us is missing the point I believe. Let's forget about the lights that do work and concentrate on the brake lights. Some work and some don't because they are controled by different switches and are on different circuits even though they ultimately cause lights to display on the back of the car.

You have NO brake lights, correct? None of the three lights work when you step on the brake pedal. You have confirmed that the fuse is good.

In my response to your original post I suggested that if all three brake lights stop working at the same time it is very often the fault of the large red round relay located behind the ashtray (bulbout sensing relay). If you remove the ashtray and the small compartment above it you will see all the relays.

If you pull the bulbout relay and remove it from the case you will probably find a bad solder connection that may become evident when examined with a strong light and a magnifying glass. I believe a new one is over $100 at the dealer. You can probably fix yours and have brake lights at no cost if you will solder the bad connection on the one you have. Another option would be to purchase one at a Pick and Pull, junkyard, or auto recycler or whatever you call them in your neighborhood.

Randy

Thanks Randy.

I removed a working bulb from one of the tail lights and the bulb out light
on the dash lit up. It did not come on when I took out one of the ones that
does not work. I will check it out. I took a peek at where the brake light
switch is located and I would rather not have to deal with that If I don't have to.

Tip

Just the two on the rear panel or all three not working?

All three not working is usually the bulbout sensor relay. Big red round relay in tray. Open it up and look for a broken connection using magnifying glass and strong light. Resolder and you should be good to go. They are very expensive new.

Randy

Hi,

When I hit the brake pedal, none of the bulbs light up. Just the ones used
when the headlight are turned on.

Tip