jmichos

I have just encountered a crazy set of problems with my 1987 928s4.

Sun cracked dash has led me to getting it professionally reskinned as well as binacle and glove box. Whilst at it, I had the front seats reupholstered, and the entire dash/binacle/glovebox/upper door trims/ centre consol and centre armrest all redone and recoloured a very light beige almost white. Also installation of red LED's in a/c control unit and in instrument binacle.

It all looks great but I paid a fortune.

Problem is that the car doesn't switch off! That's right I turn the key and take it out and the engine is still running.

The auto electrician who fitted the LED's for the upholsterer came out and reconnected the battery and tried it all again and the car turned off and on as normal. Then he left.

I then took it for another drive and it wouldnt turn off again. I had to disconnect the car from the battery.

Does anybody have any idea what is happening before I commit suicide.

jmichos

I thought I would just add, that a few minutes ago I was walking past the car and the front indicator lights went on as well as the instrument warning lights inside and the rear indicators (which were not flashing but also remained on. Nobody touched the car at all or went anywhere near it. I have now disconnected it again from the battery and left it disconnected.

Anybody's assistance would be greatly appreciated. I have searched the forums but couldnt find anything on this.

M. Requin

Sounds like an ignition switch problem to me- is it connected securely?

jmichos

It seems to be. I mean it doesnt seem loose in its position or anything like that. But you may have a point because the upholsters must have taken it apart or something in order to remove the dash and binacle. Or am I wrong about that?

Martin do you think that they may not have reconnected the wires properly when refitting the dash and binacle? Would that have such an unusual effect?

M. Requin

Could be- you could try gently "jiggling" the harness where it connects to the key switch and see if anything funny happens. Hopefully one of the electrical gurus will chime in on this.

Landseer

There was talk here a couple months ago about something that could be similar.

It was traced to the defroster switch that was sticking in the pod on an S4.

The car wouldn't turn off.

The discussion was around an electrical anomoly, whereby the defroster relay somehow provides electrical conductivity and power back onto the particular electrical bus that provides ignition.

Pull the defroster relay with battery disconnected and see if the problem recurs. I'll search for the link, since I remember the post content pretty well.

jmichos

Thanks for that, I would be much obliged.

The auto electrician is almost at a complete loss. He came today and couldnt work it out because it was working ok then after a drive it wouldnt turn off. The unusual thing is that the simptoms are not consistent. Very erratic.

I just finishing paying over $6000 on the interior so I'm quite annoyed that this has happened at all. Especially since the car did not have any electrical problems at all before I took it to them.

At least the interior looks pretty good. I'll take some photos in the morning and post them for you to see. Almost white, quite sleezy in an 80's sort of way.

Landseer

Not sure this is your problem, but it could be:

https://rennlist.com/forums/928-foru...cal-smell.html

jmichos

Very interesting. I will check the button in the morning. I do recall that when I picked up the car I did press all the buttons to make sure that they were working etc because of the work done to reskin the binnacle. Thanks very much for your advice Landseer. I will let you know what the result is in a few hours.

paalw

I had this exact same problem happen to me one week ago. Ignition would not turn off at all.

Got a tip from Mrmerlin to pull the rear defrost relay, and that shut it down immediately. It is the double relay at left bottom of the board at slots I and II.

syoo8

Yes-- I posted this a couple of months ago. Turns out that the defroster button was not fully "popped out" when I turned it off. It was half-on, half off, and I guess current to the ignition was flowing through the defroster circuit. jon928se suggested that I check the defroster button, and voila, the car shut off.

Try jiggling the defroster button. When you reinstall the pod it is sometimes easy to overlook.

jmichos

I checked the defroster button and its ok. Sticky and too snug because of the reskinning but OK. I even pulled the whole button off completely.

I didnt take photos yet because it was raining today here in Sydney. But I promise I will because it really is very out there.

I was driving to work in my Maserati and suddenly the check engine light came on and the car went into limp mode in the middle of the traffic. I had to do a u turn and go straight to Maserati and leave the car there. Then I picked up the trusty 928 problems and all and went about my business including having to disconnect the battery in the carpark to turn it off.

The auto electician contacted me again today and suggested it could be an alarm problem. I still think that something is earthing near the ignition barrel by not being insulated properly. If it is simply a wiring problem then the issue would not be intermittent. What do you guys think?

Landseer

Did you pull the defroster relay? That might be worth doing, in case the contact points self-welded inside.

M. Requin

If that button is sticky it could well be the problem. The PO had installed a pod and dash cover which caused the defroster button on mine to stick. My car would shut off, but I got a couple of dead batteries out of it before I found the problem. And a VERY hot ignition key once, as well, which I think was caused by this. Aftermarket covers removed, and no problems since. But I keep an eye on that button still when I use it. Do take Chris's advice and pull that relay, also.

Ducman82

id disconnect the LED's that were added and try it. i unhooked my batter and the lights were still on! turned out that the direct ground for my XM receiver was grounding where it was mounted to the car! so i had to make it so i could disconnect that with the "wing" nut for the batt cable.