Finding an electrical problem

[bhuey]

I am experiencing some electrical problems with my 1989 911 Carrera convertible.

While driving the 'fasten seat belt' light comes on and the radio speakers stop working. I assume this was a safety feature Porsche designed into the car. This occurs while the seat belt is properly fastened. My car has power driver and passenger seats in case that is a factor.

Can anyone provide some helpful hints on where I should look for the short? Chasing electrical problems has never been my idea of a good time.

Thanks,
Bud

[derkpitt]

Without looking at the wiring diagram, I would start by looking at the harness behind the center of the dash. See if it looks intact.
Has any of it been altered by the PO?
Is the radio a factory unit?
Does it have an after market alarm?

[bhuey]

The radio is an aftermarket unit. I will assume since you asked the question about the radio that the speakers shutting off when the 'fasten seat belts' light comes was not a safety feature added by Porsche.

Other than adding a radio and an amp I am not aware of any other modifications by the PO.

There is no after market alarm that I am aware of.

Thanks for your help!
Bud

[bigchillcar]

sounds like your car is trying to tell you something - 'get that damned radio off..let's haul ass!'
ryan

[rick-l]

When this happened to my 88 it was due to the huge voltage spikes being put out by my defective alternator.

[mackskibum]

I kind of land with Rick on this one, or possiblya faulty ground somewhere?

[bhuey]

Thanks for the tip! I never would have thought to check the alternator for voltage spikes.

Thanks,
Bud