Front Foglights

[ChrisHC]

Continuing my fascinating journey round the various non-functioning electrical systems on my car (1987 pre-facelift 325i Sport) I have reached the foglights. Neither had any live power and the O/S one had no earth. I took apart and cleaned up the switch and after something of a struggle re-assembled it, resulting in live power at both lamps. I could not find where the cable to the O/S light went to so after struggling with that for two days, I wired up a separate earth. Bingo! Both lights now worked, but I then discovered that the O/S one was coming on and off with the sidelights, not the foglight switch, the effect was originally masked because of course the sidelights and headlights need to be on for the foglights to work.
Now behind the O/S foglight was a maze of wiring that had been cut in various places and re-joined, so I have no great faith that the wiring is as it should be. I also found there two plugs, a blue one and a brown cylindrical one. The brown one seems to have an earth connection and the other side seems to come live with the foglight switch. Is it possible that the foglight should be connected to this plug, but someone has disconnected it and perhaps could not find it again, so ran a cable to the sidelight circuit? How should the foglights be connected?

[Bonymaenjack]

A blue wire is normally connected to the outside temperature sensor along with a brown (earth)
The front fog lights (right hand) ï¿aï¿aï¿aï¿aare brown (earth) from fuse 2 yellow/violet to black
(left hand) are brown (earth) from fuse 29 yellow/brown to black


http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig01.pdf

[Brianmoooore]

The earth wires from each foglight join the earths from their adjacent headlamps, before being connected to the body at the earthing stud near the front of the LH inner wing.

[ChrisHC]

Thank you both, I did see the earthing stud on the LH inner wing and that is where I ran an earth wire to. The brown cylindrical plug I discovered does seem to have a yellow/brown and a brown wire going to it, which would be right for the foglamp. I found instructions for fitting foglights here: http://www.e30zone.net/e30zonewiki/imag ... glamps.pdf and the plug does look like half of the plug and socket labelled 1 in illustration 30 63 105. I really think this must be what the foglight should be plugged into, but instead it has been wired to the sidelights.

(The blue plug must be something else entirely, the wires to it are brown/yellow and red/white as far as I can see, which looks like something to do with the fuel injectors, but why it should be there is a mystery)

Do people agree I should wire the foglight to that brown plug?

[Brianmoooore]

Use a 12 volt bulb to check for power between the brown/x and brown wires at the connector, and if it doesn't light (when the foglights should be on), connect the bulb between the brown/x and a good body earth, such as clean metal on the engine.
Does the tell tale in the instrument cluster light up?

[ChrisHC]

Yes, the tell-tale light started to light up after I got the switch working. I have checked the brown plug is live with the foglight when it should be with a tester but I will try now with an actual bulb.

[ChrisHC]

Right, a bulb connected to the brown plug lights with the other foglamp and goes out with it. I think I will go ahead and connect the foglamp to it and disconnect the cable that seems to go to the sidelight circuit.

[ChrisHC]

Success! Both foglights now work as they should and I have been able to finish installing new smiley headlights.