I have been getting an error about right side turning light not working. I figured it was a bad bulb. Finally got some new bulbs and went to change them tonight. I found that the wire going to the turning bulb was shedding it's coating for some reason. Found this on both sides oddly enough. So I cut the wire back close to the plug where the coating still looked ok and then spliced in a new wire and plug.

Put a new bulb in since I bought them then put the light back in. Still got the right turning light out warning though. So I thought maybe the pigtail from the headlight bracket inside the car to the wire loom might be bad. Pulled it out though and it seems to be fine.

Did continuity checks on the pigtail on the bracket and from the socket on the headlight assembly to the new plug and both are fine.

Went to check the fuse and found another mystery in the owner's manual. There are two lists for dashboard fuseboxes but both show "left side of dash". Ooops, obviously Porsche screwed up on this. I'm assuming the first one in the book is actually left side and the next one must be right side. Fuse is good too though. It's fuse #21 on the left side box.

Getting power to the fuse just fine but I get .05v-.06v at either side main headlight plug for the turning lights. Anyone know if there is a relay for these lights somewhere?

 

Oh and please ignore the bonehead spelling error in the headline.

 

Before digging into it too deeply - I'd suggest checking the voltage going to these lights at the connecting plug for the headlight. On the 955/957 series (which by your avatar I assume you're talking about) this is the most likely place for a bad circuit connection. And that bad connection may cause heating of the wires going to it - which can cause the insulation to harden and crumble.

The rule for electrical troubleshooting - start at one end and work to the other end. Looking for relays you're starting in the middle.

 

Boy I tell ya, I hate electrical issues. I basically did start at one end. Effectively no power at the plug to the back of the headlight assembly yet there is full power at the fuse. What I didn't do was check the voltage at the other end of the pigtail, I just pulled the pigtail and checked continuity from one end to the other.


I'll pull 'em apart again and pull both pigtails out and check at the harness plug to see if I'm getting anything there but I somehow doubt it.


Oddly, today I also started getting a warning about front side markers. I frigging hate electrical issues, they can just go in so many different directions. Did I mention I hate electrical issues?


What else is really odd is it was only the wire inside the headlight assembly that the insulation was crumbling off of. The wires on the pigtail looked just fine.

 

With the side markers joining the game I now wonder if it could be a ground issue? I found a basic dIagram of ground locations but does anyone have specific locations for grounds in this area?

 

And now today the side markers are working just fine. I haven't had time to dig back into this but I'm going to look for a loose ground in the area. I have a hunch that will fix the problem.....if I can find it.

 

The plot thickens. Ran a long wire last night and I get no continuity from the fuse to the right socket. But I do get continuity to the left socket but still no power at either. I'm assuming whatever controls and monitors the lights cuts the power to the left side because the right side is not working. It does that if a bulb is out from my experience.


I pulled the pigtail and no power at the wire loom plug either so it's not the pigtail. That would have been nice to be able to throw a new pigtail in and fix it.

 

"MYETERY" solved..... finally. When I replaced the wire inside the headlight I looked over the rest of the wires in there and everything looked ok. Turns out though the shared ground from the cornering light and the parking light was a bit frayed at the connector. Fixed it up and all seems to be well.

Did I mention just how much I hate electrical issues? This was a classic case of just about going full circle before finding what was a pretty simple solution.

I also have a sneaking suspicion that when I replaced the bulbs the first time I might have ended up with 100w bulbs which was probably why the wires were shedding the insulators in the first place. Shame I didn't see the issue with the found wire a LONG time ago.