1980 528i starting problem - BMW Forum

Dionysis · 01-09-2007, 06:22 PM

Sorry if this has been covered somewhere else, I searched but had no luck.

Up until 2 days ago I've been driving my 1980 528i sedan pretty much every day and it's been running perfectly, or at least as perfect as a 27 year old car should.

Yesterday I got in and tried to start it and nothing. It seems very much like it would if you try to start the car while in the wrong gear, not in "park" or "neutral".

With the hood up I can hear the first relay clicking when I turn the car on, but then I don't hear the second set of relays clicking when I turn the key like you normally would.

I'm not a mechanic by any stretch of the imagination but I know pretty much how things work, but I don't know where to even start with this one.

Anyone got any bright ideas?

Dionysis · 01-10-2007, 04:25 PM

Update:

After a little tinkering last night I have eliminated the battery and the starter motor, both are ok. I can short the solenoid terminals and the engine turns over ok, with the ignition on I can even start it this way.

So where else could the problem be?

I'm guessing either the ignition switch, or the switch in the auto transmission that stops you from starting the car in gear.

Anyone know where I can find a wiring diagram online so I can try and troubleshoot this further? There's a couple of links on this site but they don't seem to work.

da_bull · 01-10-2007, 07:00 PM

Pull it down in neutral and see if it will start from there. I'm like you, I think its either the neutral/safety switch or the key switch.

Dionysis · 01-10-2007, 07:14 PM

Thanks for the suggestion da bull, I've already tried starting in all gears, no luck unfortunately.

I've even tried holding the key switch in the "start" position and moving the gear selector at the same time just to see if it's sitting in the wrong position according to the markings on the shifter.

fastshivy · 01-10-2007, 07:36 PM

Buy an inexpensive probe test light. These look like an ice pick with a bulb and a wire hanging out. You can purchase one at any auto store. Get the car up in the air and find the neutral safety switch. Have a beautiful blonde assistant hold the key in the start position. You can probe the wires 1 at a time going in the switch and coming out...both should light up the test bulb. You may have 1 black wire which will not light up..this is a ground. if 1 wire lights up you are getting power to the switch so your ignition switch is good. If both wires light up the neutral safety switch is also good. It is really better to have a digital voltmeter to check resistance in the switch and a bunch of other stuff...but if you do not have one try the above. Should be easy to solve. Most likely it is the neutral safety switch. Blondes can get you in trouble probe only the wires!!!

Dionysis · 01-10-2007, 07:50 PM

Good idea, I'll get onto that as soon as I can get the car up in the air. Unfortunately I can't work on it easily at the moment. But after this weekend I will be able to get it off the ground.

Any idea where on the transmission I will need to look for the safety switch? I've poked my head under and tried to find wires heading in that direction but couldn't see anything obvious.

fastshivy · 01-11-2007, 05:26 PM

I am really more familiar with American cars. Usually they are on the left side midway on the transmission. Sometimes you can just follow the shift linkage and it will be near there. Probably on a car that old they are the only wires attached to the tranny unless the overdrive is electronic. Anyone else want to pipe in here? A good parts diagram would really help here.If you can get a repair manual that would be even better. Good luck...We love Aussies over here!

Dionysis · 01-11-2007, 05:45 PM

I've found a picture of my transmission, not terribly detailed though.

I'm guessing what I'm looking for will be the little protrusion (it looks kind of electrical) just to the right of the shift linkage?

fastshivy · 01-12-2007, 08:12 AM

It may be somewhere in that box where the shifter cable is or possibly just under the shifter itself in the console. Here is a parts site, but I am not sure they go back that far RealOEM.com Online BMW Parts Catalog

fastshivy · 01-13-2007, 06:02 AM

Try the following link, it brings up a picture of the switch.Race Parts - Auto Parts - Car Parts - The Internet Racepages - RacePages.Com OEM Volvo Volkswagen BMW Mercedes Parts It looks like when you move the gear selector one of the many wires sends a signal to the shift indicator light on the dash.. You will have to sort out which one is for the starting circuit or you can just replace the switch and hope you made a good educated guess!

Dionysis · 03-12-2007, 09:04 PM

Finally got the thing fixed, turns out it was the ignition switch, not the neutral cutout.

Ironically I fixed it about 3 days after rigging a switch between the solenoid and the battery. hehe

camper1159 · 03-13-2007, 08:24 PM

How many wires come out of the ignition?

Why did you hear a click under the hood if the ignition switch was bad?

Help us all understand!

Thanks...

Dionysis · 03-13-2007, 09:27 PM

The click I was hearing was when turning the ignition to the "On" position.

There was nothing when turning it to the "Start" position.

I have no idea how many wires there are in the ignition, I took the easy way out and had a mechanic fix it for me. *embarrassed*