924Board.org

[Neil@Bournemouth]

Hi all,
I have a problem with my 924 so any help would be appreciated...

With no key in the ignition the red dash lights glow a little (battery, oil, breaks etc).
The car starts and runs fine but when the ignition is turned off and the key removed, the car continues to run! The battery light just comes on on the dash.
Ive read that 924's suffer from regular ignition switch problems but havn't heard of this happening.

Any thoughts on what could be causing this?
Many thanks.

Neil.

[Mike924]

Hi, Neil.

Welcome to the forum!

When you say the engine continues to run. Do you mean that it continues running as normal (which would point to an electrical problem) or does it run really rough (which would be indicative of severe pre-ignition)?

Has this fault just developed or have you just got the car?

It could be a fault in the ignition switch. One way to tell would be to unplug the the connector (tricky to get at) from the switch and effectively 'hot-wire' the ignition. If it stops properly when you remove the 'hot-wire' it's most likely the ignition switch at fault. If it behaves the same as when the switch is connected, a likely cause is 'unauthiorised' wiring changes. Very hard to track down.

When I first got my car only 50% of the electrical circuits worked, and a good number of those that did work switched on other things as well! (e.g. ignition came on when the rear wiper was operated!) Most of the wiring faults were due to a very inept attempt to wire in a new radio (by the previous owner ) and another, buried deep in the centre console, nearly set fire to my dashboard!
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Neil@Bournemouth]

Hi Mike,

Thanks for the reply.

Ive had the car for about 6 months now and the electrics have been faultless. This problem has just started out of the blue so its hopefully not a previous owners dodgy wiring!

The engine continues to run as if nothing has changed and doesn't even falter. I've had to stall to get it to cut out.

I'll try the hot wire technique tonight and see if it stops the problem.

[Min]

what year and type (turbo? non-turbo?) is your car?.

Min

[Neil@Bournemouth]

Hi Min,

Its a 1984 non-turbo.

I havn't had chance to check the ignition switch yet but ill keep you posted...

[Neil@Bournemouth]

Hi everyone,

Just to say thanks for the help but i've now solved the problem.
After hours of searching it seems to be the yellow wire harness located behind the distributer thats causing the problem. When in one position the engine wont stop and in another everything works fine!

[Mike924]

I think you need to look into that a bit more closely, Neil.

It sounds to me that there is an internal short-circuit in that bunble of wires, which is causing the ignition circuit to be powered without the key. This means that two wires are touching each other that shouldn't be. If one of them happens to touch the wrong thing it could cause a fire.

You need to get inside that harness and have a look for any bare wires.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Duncan]

I had the same problem with my car: continue to run without ignition switched on and the dim lights.

It turned out the wiring harness that runs from the three pole connector just in front of the firewall near the battery had completely disintegrated.
A lot of wirefragments sticking out....
This could not be seen from under de hood, as the damaged part was all hidden behind the exhaust manifold.

It turns out this harness is NLA from Porsche. I had mine made with a special heat resistant cover.

Duncan