Engine won't turn off??? Usually we have it the other way around.

[Golfer1483]

Okay, so my newly purchased 1988 325i convertible might be a monster. The engine starts and runs pretty well, but when I turn the key to shut the engine off nothing happens. The key goes to the off position, but the engine won't turn off. The only way I can shut the engine down is by taking terminals off the battery, crazy. This is my third BMW and second E30, as I have dug into this one I feel like I might be in bad shape(over my head) and I miss my old one I sold many years ago. I had felt pretty confident in my knowledge of the cars, this one seems like it has all new problems I have never seen. Thanks in advance for any help and suggestions, by the way this is my first thread.

[iamgnat]

If the car is stopping when you disconnect the battery, you should get your alternator checked as it should keep the car running without the battery.

As far as your actual issue, first pass I'd guess the ignition switch is bad or one of the ignition system relays is wonky.

Edit: Bentley doesn't mention your issue, but pages 15:41 & 15:42 talk about how to test the ignition switch

[my1stE30]

Hello Golfer ... and welcome to bimmerforums.com .... my first thought here is that you have some sort of a short or cross-connection in your ignition switch (where the key is inserted into the steering column) ... so even in "off" position the engine electrics are still seeing 12V power supply...

... when you reconnect the battery do the dash lights come on automatically as if you turned the key to "on" before engaging the starter ... if so, then I would have to suspect a worn ignition switch

.. it could be the ignition switch ... or I have seen some other weird electrical issues caused by a series of faulty/poor ground connections

[nj325//m]

has to be ignition because in order to supply spark the ignition must transfer voltage from battery to the fuse box, ecu, coil, dist, plugs fuel pump an inj. etc. start there see if any one tinkered in there use a bently manual for wiring diagrams.

[Golfer1483]

Thanks guys I really appreciate it, I am going to look over all of the wiring I can see and also open up the steering column to see if the ignition wiring is screwy. The only thing I saw in the engine compartment that was weird was a small blue wire running from the bottom front of the oil pan. It looked like someone had rigged up a wire and connector to a sensor down there and then hooked it up to nothing. I traced it down and it goes no where. I have put 4 days of work into this thing, finally got it running and drove it last night thinking I would be doing pretty good, but my laundry list is growing. Numerous suspension components, this ignition demon, no odometer or speedometer (which the guy said was working)(and I have found some info already on here about that), knocking at left rear, transmission issue or shifter linkage (high pitched whirring noise if you lean on the shifter) and plus the normal things I already know new convert top and tires. AHHHH! I hope this baby doesn't cost me my marriage, I convinced her I should buy this and I knew what I some of what I was doing. Thanks again for the help and for letting me vent.

[thejlevie]

It could be a bad ignition switch, in which case the DME would be powered up all of the time that the battery is connected. But it could also be improperly installed aftermarket electronics that are back feeding the ignition circuit after the engine is started.

[iamgnat]

I have put 4 days of work into this thing, finally got it running and drove it last night thinking I would be doing pretty good, but my laundry list is growing.

Sorry man. Take heart that you are not alone and you have come to the right place to find a bunch of helpful and knowledgable people.

I'm in a similar boat where I thought mine was a decent DD out of the box. I knew it needed some things done, but they looked to be a few months/years down the road. Weeks was the reality In the last week or so, though, I've managed to actually take a few (minor) things off my list without new things going on. You gotta take the small victories when they come

[Golfer1483]

Okay guys, I installed a new ignition switch and the car still will not turn off. I have not gotten the chance to do much of the checkouts on the grounding and I do not know how much I am going to be able to do because I am not very good with wiring diagrams. One thing I just noticed is that when I go to turn the engine off (and it doesn't turn off) the brake light LED comes up on the service light indicator panel. The brake light LED is not on until after I turn key to off position. Any other ideas.

[jcbrown630]

The much despised electrical gremlin..... :

[thejlevie]

Okay guys, I installed a new ignition switch and the car still will not turn off. I have not gotten the chance to do much of the checkouts on the grounding and I do not know how much I am going to be able to do because I am not very good with wiring diagrams. One thing I just noticed is that when I go to turn the engine off (and it doesn't turn off) the brake light LED comes up on the service light indicator panel. The brake light LED is not on until after I turn key to off position. Any other ideas.

I'd say that something is backfeeding the "Hot in Run and Start" circuit. The only way that can happen is for there to have been mods to the wiring (like improperly installed or failed aftermaorket electronics).

[iamgnat]

Sounds like something down stream then. Possibly a relay and/or a bad ground. I don't have any real experience with the ignition/motor electrics though.

If you haven't already, I would suggest getting a Bentley and also a good voltmeter that has ohmmeter and continuity functions.

[Kreo e3o]

Hi sorry to disturb but I'm havin the same problem with my e30 what did u eventually find

[Bimmerfan84]

Could be a relay. Check DME relay. DME relay controls pretty much everything that would keep the car running.


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[Antares242]

Hello folks, I have the same problem and when I unplug the cluster the car turns off. Today I installed a new PCB and changed the pigtails but STILL my car won't turn off unless I unplug the cluster. The only thing I can suspect of right now is the SI board for which I changed the batteries before this happened. Do you think this could be the cause of the problem? Any ideas where else I should look for? If I start the car without the cluster plugged in, the engine turns of normally when I switch the key.

[jdmcfall]

Hello folks, I have the same problem and when I unplug the cluster the car turns off. Today I installed a new PCB and changed the pigtails but STILL my car won't turn off unless I unplug the cluster. The only thing I can suspect of right now is the SI board for which I changed the batteries before this happened. Do you think this could be the cause of the problem? Any ideas where else I should look for? If I start the car without the cluster plugged in, the engine turns of normally when I switch the key.

New to owning a mid 80's BMW. My car would turn off fine when I first got it. I pulled the dash cluster to install new speedo gears that were broken. After replacing the gears and putting everything back together the car wouldnt turn off when the key was turned to off. I pulled the cluster loose and was able to pry to furthest to the passenger side connection loose and then the car would turn off. If I leave it un-connected the car starts and turns off properly. However, this connection also makes the fuel/tach/warning lights etc work, so they don't work if left unplugged. My car is a 5spd so I can dump the clutch while keeping the brake depressed to stahl the engine. I have no idea what happened in the gauge cluster to cause this problem. BTW, speedo still doesnt work. I believe the sending unit on the rear axle needs replaced next.
ps - found out if this wiring connection (blue 24 pin) is left unplugged your alternator won't charge. Once connected, the voltage showed over 14volts.

[BEANCENT]

There should be a large ground wire hooked up to the front top side of your oil pan, was that there besides the weird blue wire you saw down there.