Reynard38

OK here we go again. Windows, mirrors, wipers, heater blower, foglights inop. It happened about a week ago and about 5 miles down the road it all started working again at once. I have to think it's a relay or bad ground. Anybody have any ideas about where to start looking?
If there is one thing I F#$KING HATE it's and intermittant electrical problem. Must be why I changed my major from electrical to civil engineering so many years ago.
Oh and BTW I just paid up and joined RENNLIST.

rcwelch

This may not be related, but underneath the drivers side footwell there is a large bundle of wires that were resting on a screw that had come thru something and would intermittantly short out my tail lights, starter circuit and brake lights. I finally took it to the dealer and they found the screw head, filed it down and moved the bundle of wires...been fine evey since.

Sumtoc

Not sure what MY yours is, but I have read several articles and sections in Porsche books pointing out wiring harness problems in 95-96 models. Have also seen lots of posts here on that topic if yours is one of those MYs, you should check that out.

I believe that one of those posts indicated that Porsche dealers would still replace the faulty harness at no charge if it can be proven to be the problem.

Bull

Yes, when I owned my '96, I received a recall notice (in '98) regarding the wiring harness that was very specific about the wiring running under the passenger side carpet. It advised that it could become worn and set off the airbags unexpectedly! My wife thought I was nuts (again) when I told her to keep her feet still until I got it in to the dealer because she could set off the airbags if she didn't keep still......

Reynard38

It's a '97 model. I'll take a look under the carpet tomorrow morning.

Reynard38

Dug through my manual on CD and found a diagram of all the ground points in the car. There are about 13. I'll start there.
When I have had German cars and bikes in the past electrical problems were almost always a bad ground or relay, though I will check that wiring bundle under the carpet as well.

Reynard38

Grounds checked, no defects noted in the wiring under the carpet. Either there is a relay that controls the power to these systems that is stuck, or the ignition switch is bad.

Reynard38

Well I had to admit defeat on this one and take it to German Car repair in Roswell (GA). After spending an hour with pieced together PDF's of a wiring diagram and a yellow highlighter attempting to find a common component I gave up. Of course the day I take it in it POURS rain (remember the wipers aren't working!
FWIW a 911 really doesn't need wipers above 70mph.
I hope this doesn't cut to deeply into the GHL exhaust $$

Reynard38

FIXED!! 1 bad relay and a loose solder joint in the body control module. Many thanks to Alan and Jerry at German Car Repair in Roswell, GA. Instead of ordering a new BCM for $400 or more they opened up the box and resoldered it. Total bill for diagnosis and repair is $160!
This is the difference between a mechanic and a guy that just replaces parts.
GHL budget intact!

rcwelch

What is a body control module?

Reynard38

Dunno exactly, but it's located up under the passenger side of the dash.

Glen

Great news! Several of the convertible top modules in the 964 and 993 have suffered similar failures. Thanks to You and Your mechanic on the resolution!
Regards,
Glen