Anyone have a late model ignition switch?

[jaredmac11]

I am refurbishing a 320is, don't have much history on the car but it seems like the ignition switch has gone bad.

Key will turn fine in the lock cylinder but I am not able to get power to accessories or start. Just a week ago accessories would get power but not start.

I added a push to start but it seems like the entire switch has now failed.

I'm guessing if the keys turn and it once worked, it's not the ignition lock cylinder right? Anyone have a used one before I go for new?

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[goinstrong]

We have a parts car with a good working ignition switch. It is a 1981...but is there a trick to removing the ignition switch? At first glance, it looks like the whole steering column has to come out!

[jaredmac11]

In my parts car, I removed all the key sets (doors, trunk, ignition); but left the ignition switch...

This is the thread I used to get the lock cylinder out:
http://www.bimmerforums.com/forum/sh...nition-Tumbler
You should do this so you have a set to save.

This thread should have the steps to get the ignition switch out. If you decide to part with it, I would greatly appreciate it : )
https://www.bimmerforums.com/forum/s...-ignition-lock

[amarino]

Have you tried testing yours with a multimeter and continuity test (beep mode)?

You can unplug the harness under the dash and try the leads going to the switch individually. The connector would look like this (but not ghetto wiring hopefully): https://www.bimmerforums.com/forum/s...9#post30137369

And here are what the colors mean to test: https://www.bimmerforums.com/forum/s...50#post7689550

(A) Red wire - 4mm^2 (10 gauge) - hot from the battery.
(B) Purple wire - 4mm^2 (10 gauge)- ACC
(C) Green Wire - 4mm^2 (10 gauge) - Ignition
(D) Black wire - 2.5mm^2 (12 gauge) - Starter Wire
(E) Plug to starter wire

So in ACC you should get continuity between Red and Purple
Then in Run you should get continuity between Red, Purple, and Green.
And if you hold it at Start you should should get continuity between Red, Purple, Green, and Black (black is on a wire on its own and not part of the connector)


I had mine break on the plastic housing of the electronic part years ago. Picture is dated 2013 and I probably just threw out the old one. This was when E21s were still in junkyards and before I figured I should save everything, even broken.
IMG_20131118_175403.jpg

[jaredmac11]

So dumb question but I should be checking continuity across wires at the switch side of the connector right?

With the key out, I don't get continuity anywhere, as expected. . With the key at acc I get the right continuity. With the key at run, I get continuity. Don't have a helper to test start.

What's odd is... I should get power to the dash and some parts if I'm getting continuity at acc and run, right?

Last weekend, I sorta was, but I'd have to jiggle the key and it would sorta flicker. Weekend before that only start was fussing.

The previous owner jumped the wires and inserted the necessary fuses and relays. I thougjt they wanted a race car push to start and switch panel (it was a track car) but now I know... Something was up

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[jaredmac11]

We have a parts car with a good working ignition switch. It is a 1981...but is there a trick to removing the ignition switch? At first glance, it looks like the whole steering column has to come out!

If you're removing the switch, this is the little screw. Mine was painted red. Still not much room to get the switch out from the back, I think the ignition needs to come out and it's all sandwiched together.

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[jaredmac11]

One more question, the black wire is off on his lonesome, disconnected. Where does it connect? Im not too worried since I still have the push to start button but would like to test continuity.

I guess I just dont understand how/when I can know when the key is failing, when the ignition cylinder is failing and when the switch is failing. I suppose if I get the ignition cylinder out, if the crescent mood in the back turns, it would turn the switch, as you depicted, and all would be right with the world.

[amarino]

So dumb question but I should be checking continuity across wires at the switch side of the connector right?

With the key out, I don't get continuity anywhere, as expected. . With the key at acc I get the right continuity. With the key at run, I get continuity. Don't have a helper to test start.

What's odd is... I should get power to the dash and some parts if I'm getting continuity at acc and run, right?

Last weekend, I sorta was, but I'd have to jiggle the key and it would sorta flicker. Weekend before that only start was fussing.

The previous owner jumped the wires and inserted the necessary fuses and relays. I thougjt they wanted a race car push to start and switch panel (it was a track car) but now I know... Something was up

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Pics will help to see what the previous owner did or what your wiring looks like.


Correct yeah only between the connector and the switch. Not on the side of the connector that goes to the rest of the car's wiring harness. Best to unplug it to test the switch isolated. Depending on the multimeter and type of leads it has you may be able to just jam them in the connector on the harness and leave it plugged in while you test with the key.

61311358932-Ignition-Switch.jpg

You should be able to get power and turn on the lights if you're getting good continuity on ACC and RUN.

The Black one by itself should go to the Starter by itself and not part of the connector with the Red / Green / Purple wires. You'll only get continuity between Red and Black if you hold the key in Start. Best to unplug it from the car so you only test it with the switch isolated.

[jaredmac11]

Thanks for the help. It looks pretty factory now. I disconnected the previous stuff. I have it written down how it was set up but don't have good pics.

previous state and current state (with testing leads) attached.

I tested that black wire and I get continuity when I hit start. So I wonder what gives? To me this means the key, ignition, and switch are all working; is that right?

Maybe I blew a fuse along the way or the battery is failing

[amarino]

The Black wire would go from the switch so a little plastic housing that looks like this (E) in the pics. All by itself and not part of the harness. I believe it splits off on the back side going to the car.
https://www.bimmerforums.com/forum/s...50#post7689550

2022-03-11_122855.jpg

[amarino]

Thanks for the help. It looks pretty factory now. I disconnected the previous stuff. I have it written down how it was set up but don't have good pics.

previous state and current state (with testing leads) attached.

I tested that black wire and I get continuity when I hit start. So I wonder what gives? To me this means the key, ignition, and switch are all working; is that right?

Maybe I blew a fuse along the way or the battery is failing

Yeah if you're getting good continuity between all Red / Green / Purple / Black in ACC / RUN / START then the switch is likely good (and key and cylinder as well).

Double check battery and fuses and maybe try to jump it and see if it comes back to life.

[jaredmac11]

OK, thanks. I got it running with my battery booster.

However something is definitely up because when I pulled the key it kept running
I need to do some digging. I wonder if the switch is failing despite getting continuity with testing earlier.

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[amarino]

Hmm. With your battery booster connected and the key out do the headlights come on all the way, or just the running lights? If headlights come on all the way that would mean like your RUN bus is always getting 12V.

Can check the ignition switch the same way just reverse, when its Off / key out there should be no continuity between Red and anything else.

Also check at the Diagnostic Connecter under the hood with the multimeter. Double check the ETM but one of the pins is for START/RUN bus I believe and see if that has 12V with the key Off / out of the ignition.

[jaredmac11]

Hmm. With your battery booster connected and the key out do the headlights come on all the way, or just the running lights? If headlights come on all the way that would mean like your RUN bus is always getting 12V.

Can check the ignition switch the same way just reverse, when its Off / key out there should be no continuity between Red and anything else.

Also check at the Diagnostic Connecter under the hood with the multimeter. Double check the ETM but one of the pins is for START/RUN bus I believe and see if that has 12V with the key Off / out of the ignition.

Ah yea, thats a great idea. With the keys out, headlight switch pulled, the dash lights and runnings lights power but the headlights are off. Its flickering a lot so I just think the battery is having issues.
The connector got no connectivity with the keys out, but I wonder if there is an intermittent issue where it 'sticks'? Hard to say with it sitting in the column. Im gonna pull it to get a better look.

Im gonna check the diagnostic connector, I believe its pin 15.

Ill start with getting the battery fully charged and seeing whats going on from there. Thank you!

[goinstrong]

In my parts car, I removed all the key sets (doors, trunk, ignition); but left the ignition switch...

This is the thread I used to get the lock cylinder out:
http://www.bimmerforums.com/forum/sh...nition-Tumbler
You should do this so you have a set to save.

This thread should have the steps to get the ignition switch out. If you decide to part with it, I would greatly appreciate it : )
https://www.bimmerforums.com/forum/s...-ignition-lock

Thanks for the links! I will pull all of that out, and let you know if we are keeping it or will send it on its way to you!
Tim

[HappyE21]

I have an Ignition switch already pulled if you still need it.

-Cole