Disintegrating wiring insulation in Litronics headlight assembly

So, my 04 Boxster S has been a treasure trove of hidden surprises, mostly unfortunate ones. I went to replace the inop right rear fog light bulb and discovered the socket wasn't even getting power. Then I went to replace the left front parking light bulb and discovered wiring insulation disintegrating in the (Litronics) headlight assembly. It seems a previous owner replaced a bulb in the assembly and did not reinstall the back correctly. There was a ~3/8in gap at the bottom when I removed the assembly from the car. I can only speculate that exposure to coastal heat & humidity was a contributing factor.

Wires coming from the back:


Wires inside:


Connector for wires coming from the back:


As you can see, some but not all of the wiring insulation was affected. Given the exposed wires, I was mildly shocked that everything except the parking light bulb (which did have a bad filament) was working (although in hindsight I don't recall seeing the headlights lights pivot up & down when I turned them on).

The insulation on the red/green/blue/black wires coming from the back is too far gone to save, so I’m planning to replace them by soldering some new wires in between the connectors. That should be pretty straightforward.

For the rest I’m planning to paint some layers of liquid electrical tap on all the exposed wires and cracks and hope that’s enough to insulate them from each other and keep them intact. I’m trying to disturb everything on the inside as little as possible to avoid damaging anything any further.

I’m open to suggestions is anyone has any. I’ll post updates as I’m going along.

[particlewave]

Liquid Plasti-Dip (the kind in a normal can, not spray can) works much better than liquid electrical tape. Paint it on with a small brush and do multiple coats.
It's thicker and more elastic.

[Gilles]

Laminar,

A few months ago my son and I ran into exactly the same issue (crumbling insulation with fully exposed wiring on one of the headlights) on his '02 VW Jetta that was originally sold on of the NE states.

The VW dealer was not even able to find the part number of this section of the harness, so we visit one of the imported car section of one of the large junk yards in the LA area and found a few cars with the harness section we needed in great shape, if I remember correctly we walked out of there with the connectors, harness and few odd extra parts for a grand total of $5.50 or so, and we spent way more on gas and lunch than the spares...

We swap them up with the damaged harness and everything was back in working order right away.

Woody may have the harness section you need

Originally Posted by particlewave

Liquid Plasti-Dip (the kind in a normal can, not spray can) works much better than liquid electrical tape. Paint it on with a small brush and do multiple coats. It's thicker and more elastic.

Did not know that. Excellent tip!

Originally Posted by Gilles

Woody may have the harness section you need

I was thinking about that, but it looked like the connector at the other end for the red/green/blue/black wires was built into the rear cap. I may check with Woody just to see what he has...

[rexcramer]

Let's hope that the rest of the wiring in our cars is more robust than that? That is down right scary looking.

I spent some quality time working on the headlight assembly this morning applying gratuitous amounts of liquid tape and replacing the the wires between the connectors from the back.

Liquid tape circus:


Replacement wires between connectors:


I used heat shrink tubing and the nylon mesh wire sleeving to keep the ends next to the connectors bundled and act as a strain relief of sorts to keep the flexing near the connectors to a minimum.

I carefully buttoned everything back up, reinstalled the headlight assembly, and...everything worked! Well, all the lights came on, and the Litronic lamps would tilt up when I switched the high beams on.

I'm not sure how long this fix will actually last, so I'm going to hedge my bets and look around for some donor harnesses in case I have occasion to go back in there to fix something.

[dghii]

Had the same thing happen to me on a road trip..stopped for gas at dusk and realized I had a passenger side headlight out. Ended up leaving the car at an airport and renting a car to finish the trip. Picked the car up a few days later and drove home.

I couldn't believe the mess in the headlight assembly! Like you, I repaired and all was good. Weird thing is, my drivers side assembly was fine. I searched online and realized how common this issue seems to be with German cars of this era.

Wish I'd known about the Plasi-Dip idea...I'd have tried that for sure.

[10/10ths]

And Recent Audi’s have insulation that rodents think is delicious. Big problem in Colorado is Marmots eating the wiring. Seriously.

Originally Posted by dghii

Weird thing is, my drivers side assembly was fine. I searched online and realized how common this issue seems to be with German cars of this era.

I think what accelerated mine was having the back cap of the assembly installed wrong and leaving a 3/8" gap at the bottom. It was no longer sealed at that point and allowed moisture/heat/etc. in.

I checked my other assembly (which was sealed) and there were one or two wires that had a crack - no insulation flaking off like the one above.