Need help diagnosing electrical gremlin

[philipguziec]

Actually, I've got a few electrical gremlins. I figure I may need to start pulling my hair out with a meter and wiring diagram and pulling the interior apart looking for bad grounds and the like, but I figured I'd bounce this stuff off of all of you first:

The big problem is, the turn signals, flashers, and fresh air blower all stopped working at once. There are no fuses blown and I've already tried replacing the flasher. The flasher light is not illuminated and, when I turn the flasher switch on, it lights steady instead of flashing.

Other gremlins:

The rear defroster doesn't work. Fuse is fine.

The interior lights work in reverse. In the doorswitch controlled position, opening the door turns them out and closing the door turns them on.

Anyone have any great insights on where to start looking for problems?

Thanks,

[bigchillcar]

phil,
are these problems with a car that you just bought or did all of these just suddenly happen? if so, has any recent work been done to the car that could be responsible? the rear defogger also has a relay in the back in addition to the fuse..if it's bad it won't work. so, you tried replacing the flasher relay with a new, correct one and it didn't resolve it?
ryan

[Groesbeck Hurricane]

I second Ryan! Very good advice.

Also check that a wiring harness did not get compromised, but '89 is a young car.

[philipguziec]

The light switches and the rear defroster were independent of any work. It just started happening, although the car sat for a long time before I bought it. It had 24k miles at the time.

The turn signal problem came about while I had the center console out before I installed an older style short console, so I had been thinking about starting there. I was wondering if anyone knew of a ground/wire that is a common problem in the center console.

[a911]

I had all sorts of electrical gremlins, until i discover that i didnt tighten + pole on batery. Half the car had electricity half didnt and so on...

[bigchillcar]

the flasher relay is seated properly in the socket? the symptoms were the same with both the old and new relay?
ryan

[philipguziec]

Interesting. I'll clean and check the battery terminals.

Unfortunately, yes, the symptoms didn't change when I changed flashers, and the flasher was seated quite well.

[911pcars]

Phil,
Sounds like a bad common ground. Not sure about your year, but there's usually a common ground point for many circuits under the dash. Porsche ground wires are usually brown. It might be loose or dirty or both.

A wiring diagram can verify a common ground serves these circuits that don't work.

Hope this helps,
Sherwood

[philipguziec]

That could be. I was poking around behind the dash. I'll dig around behind the dash and check the diagram.

[Groesbeck Hurricane]

Phil,

A nasty little four footed rodent could have gotten in and done damage as well. Them and roaches like to eat the insulation off wires. I've had this happen before.

[philipguziec]

I don't get the sense or smell that critters are the issue here, but I appreciate the help. I also like your Lazarus Long quotes.

[911mot]

For the turn signals check the hazard (flasher??) switch connections at the back. The interior lamp problem sounds like the bulb holder could be wired up wrongly. The fresh air motors are known to fail. Check for live feed at the multiplug to eliminate switch

[philipguziec]

Tried the hazard switch connectors. The interior lights used to work properly, then they spontaneously changed. Fresh air blower and turn signals failed simultaneously.

Thanks for the suggestions.

[bigchillcar]

i seem to recall a ground wire underneath the dash that when disconnected, the fan blower didn't work..don't recall what other circuits were affected, but if you worked on your dash as you say, that would be my suspicion.
ryan

[philipguziec]

Awesome stuff! You guys might have saved me hours and hours of digging around. I'll look into it.