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Subject: Wire up some fog lamps Author: jlatker1 as Jeff '84 733i 5-Speed : member since April, 2004 : 289 posts Posted on: 2004-07-01 22:48:35

I installed some fog lamps on my '84 733i when I first got it and I'd like to share the process with you because it was pretty easy and I've never seen it documented anywhere. I'm not going to get into the mechanicals of drilling into the front bumper and mounting the fog lamps. This post is strictly about the wiring. When you are done the fog lamp indicator will light up on the dash when the fogs are on. When you flip the high beams on the fogs will automatically shut off.

To do this project the way I did, you'll need about 30 feet of two different colors of stranded 16 gauge wire. You'll need 6 crimp-on female spade connectors, 2 male crimp on spade connectors and 1 crimp on loop large enough to fit over the bolt on the negative battery cable. A crimp tool would be nice for doing this. You'll need a set of fog lights, I used the traditional rectangular style. You'll need to purchase a fog lamp switch. I see used ones on eBay all the time, but if you want a new one, the BMW part number is 61 31 1 372 451. And you'll need three 7.5 amp fuses. Two to use and one for a spare. If you have an '83 or newer e23, the wiring for the most part is already in the car, but you may need to splice into the wiring harness like I had to do.

First remove the dome lightswitch in the dash. Use a flat screwdriver and gently pry the switch from the top. Pull the wiring harness out. Disconnect the white connector from the old switch and connect it to the new fog light switch. There is a large red connector on the same wiring harness. Connect that to the new switch. It should look like this when you are done:

Just an aside, I already trimmed my thumbnail and I promise I'll stop picking my fingers...

Next up is the wiring from the fuse block to the fog lamps. Each fog lamp has its own fuse. The fuses on the fuse block are numbers 29 and 30. They should be 7.5 amp fuses. There are two ways to do this next part. If you can locate the wires that go to the fog lamps down around the bumper then you are lucky and the job is almost done. Just connect them to the fog lamps and you are done. If you can't find the wires then you will have to do what I had to do.

Install but do not connect or crimp ends on the wires. Start running your wires from the fuse block to each fog lamp. Run one of each color wire to each fog lamp. Fish the wires through the radiator support wherever you can and wire tie them neatly. Then crimp female spade connectors on all four wires at the fog lamp end by the bumper. Decide which wires will be used as ground and which wires to uses as the hot lead to the ligh bulbs. When you've got them connected to the fog lamps it'll look something like this:



When you have completed the connection of the wires to the fog lamps you should have four wires at the fuse block. The wires that are going to be used as ground should both be connected to the spade loop and crimped. Connect the loop to the NEGATIVE terminal of the battery. Now comes the tricky part. You must slice the black covering on the wire bumdle coming out of the fuse block. Do this carefully and don't cut into any of the wires. Don't come looking for me if you do, I warned ya! Find the two wires that are YELLOW with a VIOLET stripe. Snip them so you have enough wire to strip and crimp a male spade connector onto the part of the wire that goes back to the fuse block. Crimp the last two female spade connectors to the wires that you installed that will be used for the fog lamp bulbs. Connect them to the spade connectors that are going to the fuse block. When you finish it should look like this:

• Wire up some fog lamps (pic) - Jeff '84 733i 5-Speed 2004-07-01 22:48:35 (4358 views)
  • Thanks for this information. (nt) - Oka 2004-07-03 03:20:30 (538 views)
    • Oooops Too Fast! Thanks for this information. - Oka 2004-07-03 03:25:47 (521 views)