Ignition Switch?

Post Wed Jul 24, 2013 11:35 am

Hey all,

The last 3 E30's ive ownd have all had this same problem but my current E30 is suffering the most..

when i go to start the car, key in, first 2 clicks on ignition, then the final part when the starter motor should engage nothin happens.. i normally hold the key in cranking position for a few secs and it jumps into life. as said, i ve had this problem in the last few e30's but its not botherd me so much till now. got in the other day, held the key in cranking position and nothin happend at all!! i had to go work in the e46 instead!! not happy..

started it when i got home and it fired up on the button. does this sound like a ignition switch problem? and is there a way of cranking the engine over with a bypass? just in case im out and about while i wait for parts and the bugger wont fire up.

Thanks

Post Wed Jul 24, 2013 11:58 am

Does sound like either a worn out ignition switch, or intermittent connections to it.

You can operate the starter from the diagnostic socket:

http://www.e30zone.net/e30zonewiki/inde ... Plug_Start

Post Wed Jul 24, 2013 12:49 pm

Push button start. It's the future

http://www.e30zone.net/modules.php?name ... t=ignition

Granted my version is a bit overkill for road use - but in the wiring loom you could just splice into black/yellow I believe and join to live through a dash button. Not very original or secure but sexy...

Post Wed Jul 24, 2013 1:08 pm

If this is on a auto, then by far the most likely cause of your problem is the gear selector doesn't line up with the 'P' position, and the inhibitor switch is open.
Clapped out engine and gearbox mounts are the likely cause.

Post Wed Jul 24, 2013 1:19 pm

Thanks for the response. the car in question is a manual 2.7 build. never had an auto in a E30, although i am thinking about going over to the auto side on the next one

Post Thu Jul 25, 2013 9:01 am

I have this problem on my 318i M40 although the ignition switch is only a few years old.

I fitted a heavy-duty push switch inside the cabin with thick wires joining the positive terminal of the battery directly to the solenoid...this is my emergency system to use if ever I stall the car at a railroad crossing and the express train is bearing down on me.

In addition to this...for normal key starting.....I have fitted a seperate large relay in the engine bay....turning the ignition key now energizes the relay which in turn supplies the solenoid with power through thick wires.....this is how my Jeep works, I do not know why BMW did not do the same for the E30

Post Thu Jul 25, 2013 9:25 am

Billwill wrote: I do not know why BMW did not do the same for the E30

Because the BMW wiring is about a million times more sophisticated and better designed than that of a jeep!
The current passing through the green wire of the ignition switch on an E30 supplies the ignition coil and very little else.
The DME, fuel pump, K2, K5, K9, K3 and K4 relays all provide ignition switch position 2 switching.

Post Thu Jul 25, 2013 2:03 pm

Sure Brian I cannot argue with the Green wire carrying little current....But...the OP has had this problem 4 times now and I have had it on both my E30s. The Black/yellow wire that activates the solenoid is the main culprit, I have not measured the current it takes but I believe it is a fair amount of amps.

Also there is no diode fitted on the solenoid coil, that I have ever seen, to stop EMF current back-flow which causes sparks across the ignition "start" contacts and helps burn them out.

I find that fitting a robust relay to take the solenoid current is a reliable way of extending ignition switch life and it is very easy to replace the relay if needed.

Post Fri Jul 26, 2013 8:35 am

interesting stuff, if this is the case ill replace the ignition switch and fit a relay to the system and let the relay take the battering rather than the new switch. or maybe go for a push button.. not sure yet. think it might be an idea to do both a new switch and the push button for backup, but if I have a push start ill prob just use that..

well we will see.

I just find it strange that on both mornings now I have gone out to start it and it wont spin over, I drop the missus off in the e46, come back 10 mins later and the bugger starts!! maybe it just don't like the missus! she does complain that I love the car more than her!! lol

Post Fri Jul 26, 2013 9:08 am

You can try installing a relay first...before replacing the ignition switch. The relay coil draws minimal current so the dodgy contacts on the ignition switch may be happy powering up the relay.

This is the scenario I have....ignition switch would not activate solenoid sometimes....fitted push switch directly over solenoid and starts fine. Fitted relay activated by ignition switch...been working fine now for about 3 years now.

If I pick up any more problems with using the ignition key and replacing the relay does not help then I will replace the ignition switch because the "dodgy" contacts would finally have failed.

Only problem with my push button setup is that it is "live" at all times so if I bump it by mistake while the car is in gear I may have a bumper bashing

Post Sat Jul 27, 2013 2:21 pm

ok, sounds like it might be worth trying the relay out first and see how i get on. what ignition wire did u take the switched feed from? and where did you send the output to?

Post Sun Jul 28, 2013 10:17 am

mrb27 wrote:ok, sounds like it might be worth trying the relay out first and see how i get on. what ignition wire did u take the switched feed from? and where did you send the output to?

You need to interupt (ie. cut) the Black/Yellow wire that normally goes from the ignition to the starter solenoid...you will find it going through the large black connector at the bulkhead. Use this wire, coming from the switch, to now energize the one side of the coil on your new relay...the other side of the coil goes to ground somewhere.

The section of Black/Yellow wire that goes to the solenoid you connect to the normally-open contact in the relay and the common contact picks up +12 volts directly from the battery via an inline fuse....15 Amp should do.

Post Sun Jul 28, 2013 11:05 am

Billwill wrote:The section of Black/Green wire that goes to the solenoid you connect to the normally-open contact in the relay and the common contact picks up +12 volts directly from the battery via an inline fuse....15 Amp should do.

Shouldn't that be Black/Yellow, i.e., the other side of the wire you cut?

Post Sun Jul 28, 2013 12:47 pm

If you cut the black/green, you'll have very useful push button control of the heater, windows and roof.

Post Sun Jul 28, 2013 3:26 pm

Speedtouch wrote:
Billwill wrote:The section of Black/Green wire that goes to the solenoid you connect to the normally-open contact in the relay and the common contact picks up +12 volts directly from the battery via an inline fuse....15 Amp should do.
Shouldn't that be Black/Yellow, i.e., the other side of the wire you cut?

Yes you are right, my bad, I meant the Black/Yellow...will fix it with a ninja edit so I do not look too stupid

Post Mon Jul 29, 2013 10:10 am

willnz wrote:Do you have an alarm/immobiliser fitted? Or one in the circuit you dont know about? They are by far the main cause of the issues you are experiencing.

yes i do have a working clifford alarm/immobiliser on my cabby, however none of my previous E30's have had alarms/immobiliser's and are all acting the same

Brianmoooore wrote:If you cut the black/green, you'll have very useful push button control of the heater, windows and roof.

LOL!

Billwill wrote: Yes you are right, my bad, I meant the Black/Yellow...will fix it with a ninja edit so I do not look too stupid

Too late

Think im gonna try out a relay first that billwill suggested and see how that works out, it does sound very logical, only takes a few mins to set a relay up after all.
Thanks for the info/advice guys