relays

[dave b]

i have a 1988 560sl and every so often it just shuts off like you turned the key off after a short while it will start like brand new i heard it might be a relay inside right hand kick panel help it is dangerous to drive

[RadioTek]

There are two "usual suspects" for this.

a) The OVP (Over Voltage Protection) relay, which is what you are referring to.

b) The switch portion of the ignition switch assembly. If you wiggle the key in the lock, you might be able to start the car. If it does, the swtch is the problem. There are descriptions of the procedure for changing it out on the forum.

Good Luck.
Scott

[dugald]

Add a 3rd suspect, the fuel pump relay located behind the glove box on 560s.

[abiby]

I'm with Dugald on this one, with the ignition switch a close second.

Sadly, actually diagnosing an intermittent like this is a pain. Often you end up just being a parts changer.

[Walrus]

Originally Posted by abiby

I'm with Dugald on this one, with the ignition switch a close second.

Sadly, actually diagnosing an intermittent like this is a pain. Often you end up just being a parts changer.

ditto this.
I would not suspect OVP in this case.

[dave b]

ok will try to find all of them thank you all for your help do you have any idea what would cause them to fail like heat age short in system??????

[coleyjf]

Originally Posted by Walrus

ditto this.
I would not suspect OVP in this case.

I Agree that it doesn't sound like the OVP relay - an OVP relay fail will normally only drop down the power rather than cut off the engine completely as I've had happen myself recently

[kchemers]

I would have to go with the fuel pump relay, had the same problem with an 89 300TE, replaced the fuel pump relay and problem was gone