E36 BMW brakelight question

Apparently the brake lights in my 328iC do not come on when I step on the brake UNLESS the engine is on. I assume this is normal for this car.

It is definitely NOT normal for any other car I have ever owned.

So I may have just replaced a brakelight switch, and suffered a mild back sprain from the associated underdash contortions NEEDLESSLY.

Anybody heard of brake lights not coming on unless the engine is on? I'm curious.

They should work with the key in the #2 position whether or not the engine is running.

Giant Purple Snorklewacker wrote: They should work with the key in the #2 position whether or not the engine is running.

Yup. That's what it does. I've never known a car that wouldn't light up the brakelights if you stepped on the brakes even if there was no key in the ignition. Learned something new today.

That is BMW for you.. my TI is the same way

It's funny. I just kind of took it for granted. I mean it's not the kind of thing I check very often. The display mentioned some kind of "light failure". When the brake lights didn't come on, I figured "that's it!". Wrong!

Now I'm investigating a mysteriously good bulb not working in a particular socket on the outboard rear taillamp. No corrosion. Looks nice and clean.

Interesting. I haven't noticed if my E30 is like that. My VW is not. The brakes lights will work regardless of the key, which I found out the hard way when the switch failed in the 'on' position.

Oddly enough, the aftermarket harness I installed in our Spitfire was diagramed to have the brake lights key-dependent. I disagreed and wired them to be independent. Fortunately, when you are re-wiring a car, you can make such design changes if desired. Of course, there would be considerable difference in the wiring between a Spitfire and a modern (even E30 era) BMW.

E36s are bad about giving you a dashboard warning about a brake light being out even when they are not. As I recall, using a real BMW bulb rather than aftermarket usually clears it up.

Well, I've got a wiring issue, apparently. There are two taillight bulbs each side. The right side is fine. The outboard bulb on the left side does not work. If I switch the bulbs, the right one still works, and the left doesn't. I can't find any issues. This is the taillamp unit that the PO had replaced with a new unit.

make sure you are getting a good contact in that socket

It's not a contact matter. I've checked all the contacts in the socket with a voltmeter with the parking lights on. There's no voltage at that socket.

I find it curious that there are seven wires in the harness plug to that taillight, but only six pins in the taillamp assembly. On the right side, there are six wires and six pins.

Also, the wire that has no pin carries 12 volts when the parking lights are on. Is my taillamp assembly missing a pin? I checked closely with a flashlight. There's no evidence of a broken pin. Maybe the taillamp assy. is the wrong one? Like I said, it had been replaced recently by the PO.

I'm about ready to start pulling my hair out.

Hmmm. I'm beginning to think that it might be the wrong part. Pelican lists a few different numbers for 318, 328, etc. etc.

Any E36 328iC owners want to pull the plug off their driver's side tail light and tell me how many pins they see?

If its an aftermarket lamp a lot of them were wired wrong you have to swap some pins around. Look on bimmerforums. I'd pull it up but I'm on my phone

mrhappy wrote: If its an aftermarket lamp a lot of them were wired wrong you have to swap some pins around. Look on bimmerforums. I'd pull it up but I'm on my phone

I know it's a replacement, but the appearance is stock. Not sure who made it, but it doesn't say "BMW" on it.

Is it possible to get inside the assembly? If I've got to cut it open, fix it, and glue it back together, I might just get the right part and call it done.

I had a problem with my brakes lights on my E36, they would randomly not work on the various positions. Sometimes the left light would not work, and then later the right or center would not work. Every time you started the car a different one was not working. It was under warranty at the time, but still took them like 6 months to diagnose the problem. It was something like a faulty board I think. It's been a long time, but I seem to remember them replacing most of the components and it still had this problem.

My dad's 5 series now has an issue where the brake lights will come on and stay on until he "reboots" the system by pulling a fuse. The dealer has yet to find a cure for it.

Always wondered though if anyone else had as much brake light problems with theirs as I had with mine.

Ah, the joys of E36 ownership. I also sprained my back replacing the brake light switch on mine. Common failure item. Went through quite a few brake lights in the three years I owned the car as well.

Even if your brake light switch didn't actually fail it is good that you went through the process of changing it just like the rest of us.

PeterAK wrote: Ah, the joys of E36 ownership. I also sprained my back replacing the brake light switch on mine. Common failure item. Went through quite a few brake lights in the three years I owned the car as well. Even if your brake light switch didn't actually fail it is good that you went through the process of changing it just like the rest of us.

So I'm in the club now? The E36 Back Sprain Brake Switch Club?

Yup, you are in the club. Have you gotten around to changing the cabin air filter yet? That's the next level.

PeterAK wrote: Yup, you are in the club. Have you gotten around to changing the cabin air filter yet? That's the next level.

No, not yet. Is it memorable?

The one in my wife's A6 was a breeze.

I suggest you play some Tetris to prepare yourself for the mental gymnastics which are required to change your E36 air filter.

as somebody who always runs with the windows or at least the sunroof open (yes,. even in winter) I find cabin filters silly.

Left Side taillight is also used as the rear fog light in europe.

You guys are taking the mechanic's short bus if you think an E36 is a difficult car to work on. It is probably one of the easiest to do almost everything on since the era of carburetors.

You can swap the entire suspension in 3hrs... clutch job? 2hrs. Oil change - 5 minutes and no mess. The brake light switch isn't even a job - you break the old one out, stick the new one in and push the ring down.

You should all spend eternity replacing Jetta timing belts and 944 clutches for your insolence complaining about BMW cabin filters. GAH!

I do agree with you, GPS.. so far the hardest job I have had on my Ti was doing the Driver's side suspension arm. It was tedious to give the nut holding it on little quarter turns with the little bit of space the car had there