wiring ignition switches

I'm wiring the ignition on my 318is to some switches and need a little help on identifying the wires.
I know the red is hot all the time, Black is the starter? Violet is acc?
Heres a picture of all the wires; 1 red, 1 black, 2 green, 1 violet, 4 brown with different color lines.
Thanks!

What year is your 318 .I can put post a wiring diagram for you but BMW loves to change stuff.

Thanks, It's a 1991 318is.
Yeah, I was able to find a wiring diagram but it wasn't exactly the same

Inside the drivers door there's a vin tag inside the drivers door on the B piler it should have a date on it when the car was built early cars and later cars are not always the same but if you don't have the factory manuals it won't show you the differences /they usually do updates.in the books.

Hard to tell the colors from your picture but most of them have a stripe through them ie. the two green wire have stripes through them.

Could you give us some more detail please of exactly what the colors are.

Is that picture showing us the leads coming off the ignition switch....what ignition switch is it? ie. is it for a 318is or for a M50?

Or is the picture showing us the end of the M50 harness?

The picture shows the leads off of the ignition switch for an e30 318is. The wires i havent identified are solid green, green w/ white stripe, violet, brown w/ red stripe, brown w/ blue, brown w/ green, and a solid brown.

Originally Posted by austenjm90

The picture shows the leads off of the ignition switch for an e30 318is. The wires i havent identified are solid green, green w/ white stripe, violet, brown w/ red stripe, brown w/ blue, brown w/ green, and a solid brown.

OK none of my diagrams have those colors.

Red is probably +12 volts and you can use a meter to see what happens as you move the switch from position to position.

First position is nothing switched on.

The first click would be to supply power to the accesories such as the radio, next click is for ignition ON and final spring-loaded click will be for the starter motor.

If your running an M50 now did you use the E36 engine harness. What are you using for an ECU(stock E36,stand alone unit ,ect.).You might be better off wiring in an E36 ignition if your using the rest of the harness anyway.

I haven't had the car all that long so i'm not sure as to the specifics on the ecu and wiring harness. Although I think i've got it figured out.
Brown/green and brown/red go to the seatbelt indicator. Only one I havent gotten yet is brown and brown/blue, this diagram has both but I'm not sure what they go to.

Plain brown on any BMW wiring is always ground (earth).

Originally Posted by hornhospital

Plain brown on any BMW wiring is always ground (earth).

The circuit diagram posted shows the Brown wire internally connected in the switch to the Black/Yellow wire which is always the positive start lead going to the solenoid so I would be wary of connecting that brown wire to ground.

@OP, It is not rocket science to measure the ignition switch with an Ohm-meter to see what connects to what when the key is moved from position to position. maybe some leads will be unused

Originally Posted by Billwill

Red is probably +12 volts and you can use a meter to see what happens as you move the switch from position to position.

Originally Posted by Billwill

@OP, It is not rocket science to measure the ignition switch with an Ohm-meter to see what connects to what when the key is moved from position to position. maybe some leads will be unused

THIS

looking at the colours is MADNESS in a BMW. they change month to month year to year.

you need to USE the ETMs (electronic troubleshooting manuals) for your car and go from there. it will show the switch and what wire goes to what etc etc. easy.

The problem is what harness are you hooking this switch to an modified e30 or an e36 because there not the same.Even the keys are different some of the early single vanos ECUs have to be programed to the car so you need the right harness to do it. So you really need to know what your working with or it's not likely to work very well .Who put the M50 in your car? Can you ask them if they know what's up?IE a list of what parts were used for the conversion.You can just hot wire a switch to start your car and a switch to turn on your engine harness .

Thanks for the help, i got it running. Whenever i get the chance ill post a wiring diagram of what i did for anyone to reference.

Heres a rough sketch of how I hooked it up. Connected the red 12v wire to one side of the acc and on switch. Other side of the acc switch is Violet, on switch is connected to both greens and the brown/blue wire. I ended up not using the brown/green and brown/red. Black/yellow (starter) is powered by a relay connected to a momentary start switch, didnt need the two relays at the bottom.

Originally Posted by austenjm90

Heres a rough sketch of how I hooked it up. Connected the red 12v wire to one side of the acc and on switch. Other side of the acc switch is Violet, on switch is connected to both greens and the brown/blue wire. I ended up not using the brown/green and brown/red. Black/yellow (starter) is powered by a relay connected to a momentary start switch, didnt need the two relays at the bottom.

Hey Austen, I found this post via google search and hope you can help. I've looked at every wiring diagram including the factory manual and can not find what this green/white stripe wire powers up. It is not shown coming off the switch at all. Any guidance you or any board members could give is greatly appreciated. We are building a race car out of this with a custom switch panel and I'm not sure if this wire needs to be hooked up. Thanks in advance

I cant remember off the top of my head what the green/white wire goes to, but I can tell you how I hooked mine up. It's worked great so far!

I used two switches and a momentary push button. One switch acts as the first key position (acc), the other switch is the second key position (on), and the push button is the starter (ign).
- The acc switch I connected one end to the red wire (+12v) and the other end to the violet wire.
- For the on switch attach the red wire (+12v) to one end and the green/white, solid green, and brown/blue wires to the other end.
- Probably not necessary, but I used a relay to power the starter. I did this so that the starter can't be engaged without the second switch turned on. This also let me use a fuse and low amp switches. One side of the relay attach the red wire with the momentary switch and a ground wire. On the other end of the relay I attached the red wire and the black/yellow starter wire.

Probably more than you wanted to know haha. Hopefully this helps and isn't too confusing.