Headlight harness plugs wiring help needed

[Mike30Man]

Hello
I am putting back together the front end of my 1991 325i vert. It was taken apart a long time ago and I do not remeber how all the wiring went. I got the headlight, side markers, and metal bumper lighting all hooked up. I will not be using the fog lights for now they are taken off. So no connectors should be left dangling besides the fog lights but somehow i got a c couple left over. Looking up the part numbers and diagrams didn't seem to help. I'd put the car together with them left out but worried if any of them are responsible for any important sensors etc. The wiring loom im referring to runs across the front of the car in front of the radiator/ above the metal bumper and the wires im talking about exit on the left side by the headlight and on the right side by the headlight also



A. This is on the left headlight side of the harness. This 3 pin connector housing sticks out with almost no slack. Part number 1 378 410 plug housing
B Left side Some hacked up wire with 2 endings one has some sort of bracket looking thing other is just a wire


C. This is on the right side by headlight. A single wire splits into 2 on one end housing same as A 1 378 410 the other end is a 2 pin housing 1 378 400
another view of C

D, Also on the right side of the loom/ harness is this 2 prong connector


E.Finally on the right side there is this housing which has one female prong hole on top and 2 male small prongs on bottom.

F. Forgot also on the left side this wire that has 3 loose wires sticking out.
Any help or guidance will be greatly helpful and appreciated. This is holding me back from getting the car put together.

[Mo Brighta]

Wire colors are a great way to tell the general function of any and all things electrical in a BMW. If you can get a look at the colors of the wire insulation, you may get closer to the solution. You may have to slide the sheathing back and wash off some dirt to get to the real color beneath.

Generally, a brown wire is ground, and a brown wire with a color stripe means ground with some condition - door open, for example, for the dome lights.

The 'power wire' is generally going to have a main color of violet, green, or red with a color stripe. This indicates when it is hot- red is hot all times, violet is hot with key in 'I' (accessory), and green is hot with key in run or position II (ignition on). My 2002 has a Black wire with a yellow stripe, if I recall, for 'Start'. This may be the same in your 325ic. But I digress - starter wires are hard to confuse with any other (diameter and location are clues). Yours are most assuredly NOT starter wires.

For lighting, things get strange. Headlights have a main color of white (highs) or yellow (lows) and running lights grey with several different stripes. Turns are generally blue with red or black, in most cases. Grey/red is usually instruments, switches, license plate, side markers, stuff like that.

I'd check sensor wires up front - think 'coolant temperature' and 'auxiliary fan' and stuff like that.

Another way to tell is by when they get power. Do you have a voltmeter? If there is a hot lead in a particular key position, see if putting the fuses one by one kills power to that wire.
OR, turn everything on one at a time, and test for power the same way by turning it OFF. You might need to start the car for some of these tests. I'd rest the voltmeter on the windshield so you can sit in the driver's seat while fiddling with all those switches and see the needle.

Happy Hunting!

[808ETA]

Wire colors are a great way to tell the general function of any and all things electrical in a BMW. If you can get a look at the colors of the wire insulation, you may get closer to the solution. You may have to slide the sheathing back and wash off some dirt to get to the real color beneath.

Generally, a brown wire is ground, and a brown wire with a color stripe means ground with some condition - door open, for example, for the dome lights.

The 'power wire' is generally going to have a main color of violet, green, or red with a color stripe. This indicates when it is hot- red is hot all times, violet is hot with key in 'I' (accessory), and green is hot with key in run or position II (ignition on). My 2002 has a Black wire with a yellow stripe, if I recall, for 'Start'. This may be the same in your 325ic. But I digress - starter wires are hard to confuse with any other (diameter and location are clues). Yours are most assuredly NOT starter wires.

For lighting, things get strange. Headlights have a main color of white (highs) or yellow (lows) and running lights grey with several different stripes. Turns are generally blue with red or black, in most cases. Grey/red is usually instruments, switches, license plate, side markers, stuff like that.

I'd check sensor wires up front - think 'coolant temperature' and 'auxiliary fan' and stuff like that.

Another way to tell is by when they get power. Do you have a voltmeter? If there is a hot lead in a particular key position, see if putting the fuses one by one kills power to that wire.
OR, turn everything on one at a time, and test for power the same way by turning it OFF. You might need to start the car for some of these tests. I'd rest the voltmeter on the windshield so you can sit in the driver's seat while fiddling with all those switches and see the needle.

Happy Hunting!

Good info!