Rear foglight not working

[johnmaccow]

Built the car back up from rolling shell and fitted m52
89 facelift, all other lights work fine but rear fog doing nothing, changed bulb, cleaned connections and fitted good relay.
No light on dash when button pressed
Anyone got any suggestions?

[paultv]

Are your headlights set to ON - fogs only work in this condition.
Doess the relay K8 click when you press the switch?
Have you checked fuses 29 and 30 - 7.5 amp one for each lamp.
if no relay click then check pin 30 after pulling relay K8 for 12 volts when your hadlights are on.
The dash lights gets its power through fuse 29 whci activates the left hand fog light.


Let us know after checking all this out.

Paul

[BenHar]

Try taking the switch apart (watch out for pingfuckits) and cleaning it.

Ben

[Brianmoooore]

paultv's advice would be excellent if it were your front foglights that don't work, but since the problem is with the rears, I wouldn't recommend following it in this case.
The first thing to do is check fuse15, then pull out the switch and remove it from its plug. With the ignition and headlamps on, use a short piece of wire to link together pins 2 (yellow/black wire) to pin 4 (grey/purple wire).
If the foglights now light, the switch is at fault, so follow BenHar's advice above. Dismantle the switch with the buttons facing upwards.
If the lights don't work after linking pins 2 and 4, turn the ignition and headlamps off, plug the switch back in, turn it on, and connect a piece of wire between the battery + terminal to the fuse wire in fuse 15. On most types you can access the wire or link through a slot or hole. Alternatively, pull out the fuse and push the wire into the hole for the fuse leg nearest the outside of the fusebox.
Do the foglights work now?

[paultv]

Ah yes, I'm obviously blinded by the use of the word rear! My bad!

Paul

[johnmaccow]

Il give it a try one night this week lads and thanks a lot, just need to seal small leak from down pipe join and wire my fan and rear fogs and it's about ready for test finally

[johnmaccow]

Just been up to have a poke about n bloody headlights are off now.
Rear lights and number plate lights are on and side lights but no headlights and no power at fuses.
Bloody hate electrics

[Brianmoooore]

Have you done the tests I requested in my last post yet? In the UK version of lighting wiring (different from the on line circuit diagrams you may find) the foglight and headlamp circuits are closely connected.
Do you have a 'check' module in the roof, behind the interior mirror?
Do you have dim dip headlamps?

Pull out relay K4 and short together pins 30 and 87 (not 87b) of its socket with a piece of wire. Does that light the dipped headlamps?

[johnmaccow]

Been up at tried again earlier Brian, I've no check module in the roof. It's a 89 F plate which I think had smileys in and headlight wash system but has bullseyes in when I built it back up if that makes a difference.
Tried shorting them together but no luck, no power at fuse either.

[Brianmoooore]

If shorting 30 and 87 on K4's base produced no power at the dipped beam fuses, 13 and 14, as well as not lighting the headlamps, then there's something strange happening. Check for power at pin 30 of the relay. This should be connected directly to the battery + terminal.

[johnmaccow]

Il try to trace it next weekend mate and let you know what I find mate but thanks for the help I'm useless with electrics. I need to wire my electric fan in so need to lift fuse box to plug in so will have a look.

[HJ1981]

Both front and rear fog lights were not functioning when i got my E30.

After chasing fuses, relays, wires, looking for any corroded connections etc i ended up purchasing a brand new switch for €80 at the dealership.

[Brianmoooore]

Both front and rear fog lights were not functioning when i got my E30.

After chasing fuses, relays, wires, looking for any corroded connections etc i ended up purchasing a brand new switch for €80 at the dealership.

Many an E30 foglamp problem has been as a result of fog lamp switch troubles, but the correct procedure is to prove this or otherwise by conducting simple tests, as I've detailed further up the thread. Random parts swapping can introduce problems that you didn't have before, resulting in simple electrical problems become complex electrical problems.
I've diagnosed many faulty fog light switches over the years, and not one has failed to respond to dismantling, switch cleaning fluid and silicon grease, which will put them right for the next thirty years without boosting BMW's profits.

[HJ1981]

Both front and rear fog lights were not functioning when i got my E30.

After chasing fuses, relays, wires, looking for any corroded connections etc i ended up purchasing a brand new switch for €80 at the dealership.

Many an E30 foglamp problem has been as a result of fog lamp switch troubles, but the correct procedure is to prove this or otherwise by conducting simple tests, as I've detailed further up the thread. Random parts swapping can introduce problems that you didn't have before, resulting in simple electrical problems become complex electrical problems.
I've diagnosed many faulty fog light switches over the years, and not one has failed to respond to dismantling, switch cleaning fluid and silicon grease, which will put them right for the next thirty years without boosting BMW's profits.

Correct, hence why i chased the system first than spending €80 and playing roulette to see how things turn out, I learned about fixing switches much later down the road.

[johnmaccow]

Finally, I see the light lol
Yes iam a massive tit, one of the relays was 4 pin not 5.
Is a couple of set ups of wiring and relays and having built the car from being stripped I never noticed.
Good thing is 2 good 5 pin relays later I have headlights and fogs.