Right side parking lights out?????

mthomas58 · 05-12-2007, 10:26 AM

Right side parking lights out. Blows fuse immediately when lights are turned on. Have pulled rear light assembly and checked all connections and they are good. Bulbs are also good.

What's next?

Going to pull front light assemblies now.

Any other suggestions?????

Thanks!

mthomas58 · 05-12-2007, 12:26 PM

We just checked the front assemblies- all looks good. Where might the culprit lie?

rsrfan · 05-12-2007, 03:23 PM

Check all your grounds. Went through the same thing a couple of months ago and it ended up being the license plate lights of all things.

JP

mthomas58 · 05-12-2007, 03:55 PM

JP, I just saw your post while searching....I'll give it a try. Did your plate lights work ok (mine do).

Thanks!

rsrfan · 05-12-2007, 05:18 PM

They did. I ended up going through every lighting circuit on the car pulling bulbs and cleaning contacts until finally after cleaning the license light wires and reattaching same, the parking lights worked. It was a long process, but I became intimate with the car.

GOOD LUCK.

JP

mthomas58 · 05-13-2007, 07:08 AM

Have confirmed only the right side parking lights are on the circuit. The license plate lights and engine compartment lights are on a different circuit. There is only one wire connected to the fuse (gray with red stripe) not seperate wires to the front and rear lights as other years may have.

Have checked all housings and bulb wire connections and no problems found.

Have pulled all bulbs out and turned on lights....fuse still blows.

Unpluged rear tail light harness at the oil cooler, turned on lights and fuse does not blow.....front lights on.

So, I guess I have isolated the problem to the rear plug or rear plug downstream to the tail light assembly.

What next?

84porsche · 84porsche's Garage

I had a similiar problem with the lights. I found that the fuse I had installed was not properly positioned and the contact kept slipping. Just a thought.

rsrfan · 05-13-2007, 08:49 AM

Mark,
It looks like you are on the right track. About all I can add would be to check the plugs with a multimeter or similar tester for voltage. Hopefully, one of the more experienced members can give accurate troubleshooting steps from here. In most cases it will end up being something relatively simpe.

JP
'

mthomas58 · 03:54 AM

OK, I pulled the tail light harness out of it's mounting hole and stripped the wrapping to inspect the wires for breaks, bare spots, etc. All looks good. Problem has got to be from harness plug to the tail light assembly b/c when unplugged fuse does not blow and front lights work.

I have removed and reattached each connector, so there are no corrosion issues.

What am I missing????

mthomas58 · 05-14-2007, 04:00 AM

Blew fuse in my meter while testing the housing wiring and harness plug/ receptacle, so not not finished here yet.

In the meantime, addl searching led me to the headlight switch as a possible cause of the parking light short. Any advise here?

orph · 05-14-2007, 04:54 AM

Not sure if this will help, but I had the same problem 5 or 6 years ago. I note your's is a 1987, and the issue I had was with my 1986 930, supposedly the only year where this was applicable, but you never know ! Here is the respective post from back then:

Hmmmmmm........sounds very similar to a problem I encountered. The problem is with a bad diode. For 1986 only, Porsche used a diode in the wiring for the right side parking lights.

It is in the wiring right under the dash. On the back of the light switch follow the grey wire and you will find this rectangular block inline with the wire. Kind of like a fuse holder but, it rectangular, the diode is inside the holder. I can't remember the Porsche part number right off hand, but I checked one time and it was like $18.00 from a dealer for the diode. Being the cheap bastard I am, I just went to a electronics store and bought a 4N1004 diode, worked like a charm. If your in a pinch, it will work without a diode, but I'm sure Porsche must had some reason why the diode is there. I've checked The left side parking light circuit does not have the diode.

mthomas58 · 07-10-2007, 04:44 AM

Quote:

Originally posted by rsrfan
They did. I ended up going through every lighting circuit on the car pulling bulbs and cleaning contacts until finally after cleaning the license light wires and reattaching same, the parking lights worked. It was a long process, but I became intimate with the car.

GOOD LUCK.

JP

Just closing the loop on this thread. Recently had the car at the dealership to have the A/C evacuated and recharged. Had them troubleshoot the running light problem while it was in there. Tech had nearly three hours invested in troubleshooting......going through the entire wiring harness disconnecting cleaning and re-attaching every connection.

After finishing up the process in the right front headlight bucket while working on the turn-signal connectors, the circuit breaker stopped tripping. Funny thing is Tech said that he doesn't know exactly what he did to fix the problem but its working now- DON'T YOU JUST LOVE ELECTRICAL ISSUES??????????????