E30 electrical (headlights sometimes work)

[montokboy]

I was wondering if anyone out there also has had problems with the headlights. I have a 1986 325e, and when I pull the knob all the lights go on except the headlights(often). So I replaced the knob switch(board), but still having the same problem, checked all relays, bulbs, and fuses. The headlights work half the time and I can't figure out what it is. If anyone has any advice I would greatly appreciate it.

Sean

 

[rjp325i]

Could a bad ground be the problem?

 

[montokboy]

Ground?

I guess it could be, I appreciate your reply. So I guess I will have to just look thru all the wiring...it puzzles me that the parking lights and all work..Ive even been seeing if its heat from the engine causing somehting to get hot and interfere with the headlight electrical.

thanks again
Sean

 

[jrt67ss350]

I know you said you checked all relays, but this does sound like either a grounding or a relay problem to me. Might want to check the headlight relays again just to be sure.

 

[bichmgnt]

Also check to make sure that all the connectors for the relays are in their sockets. It's possible one has pushed out keeping the headlights from coming on all the time.

Steve

 

[Ryan Stewart]

so your headlights shut off automatically when you turn the car off, leaving just the parks on?

apparently pin 30 is the one on the relay that gives it a signal that its ok to let the lights on, its like a saftey net.

 

[montokboy]

headlight syndrome

First, thanks to everyone for posting advice.

For the last post, my car's low beam headlights sometimes don't work, when the car is turned on, the parking lights however work fine.
I rechecked the wiring but didnt find anything loose or not grounded properly, I would think if something was loose or grounded improperly while the headlights are on..if I move the wires around..the headlights should show something...but nothing happened. Does anyone ahve any experience with heat affecting wiring?

 

[bichmgnt]

Just to be sure, montokboy, you do know that when the key is off or in the accessory position the healights won't come on but the parking lights will. The headlights only turn on when the key is in the engine running position. I'm sure you know that but sometimes you gotta make sure.

Your wiring should not be affected by heat. There are only simple relays and wire, none of which should be affected much by heat. Power for the headlights does not go through the headlight switch but power for the relays that activate the headlight circuits does.

Try this. Turn your headlights on (with the key in the engine running position, of course) and try tapping on the K3 and K4 relays. They are the only relays with contacts in series with the headlights that could affect their operation. If you're careful you can even take these relays apart, at least the metal ones, and see if the relay contacts are clean. If the contacts are pitted and corroded you can clean them up and see if they work better.

I would suspect the low beam relay before the high beam relay but both can cause the problem you're seeing with the low beams. However the low beam relay is very much more the likely culprit.

Another thing that could cause it is the ground wire on the headlight switch. If that one's dodgy it would screw things up as well.

Good luck.

Steve

 

[mikev]

My sidelights and dipped beam work every time but the full beam doesn't works when i flash but only tempermentally when i need them on. wireing on these cars sucks and lets face it electronics arn't BMWs forte!

 

[montokboy]

thanks

Thanks everyone for all your help. I checked everything out, I didnt find anything wrong, but it seems to work fine now...maybe it just needed an exorcism

 

[bichmgnt]

Mikev, it sounds like you've got a bad high beam light switch or possibly the wires going to it. It might also be the connector to the switch. I had an old Dodge with cruise control on the turn signal stick that was intermittent and found that the wires inside the steering column had broken after repeated flexing.

I just replace my headlights with CIBIÉ Complex-Surface Reflector headlamps and had to do some rewiring to accomodate the fact that the low beams don't have a high beam filament, similar to ellipsoids. I learned a lot about the headlight wiring because of it and can help if you have any questions.

Steve