Wiring Harness Repair

Wiring Harness Repair

While lying on the floor under my car preparing to instal a replacement alternator I made an unpleasant discovery. The wiring loom to the alternator passes down between the timing belt and the block on the left hand side. The covering looked a bit tatty so I pulled a section off. All the cables were bare for about 3 inches or so and have been for some time, they were green and a lot of the strands were broken.
The cables I am refering to are the battery jumper lead,alternator power and fields wire and oil pressure wires. They are in a plastic covering and run across the front top of the engine then disappear down behind the timing belt, this is were the problem occurred. When I pulled the cable out and pulled the rest of the covering off it became obvious I would have to replace the lot.
For a bit of comic relief I rang the Porsche parts people in Sydney and was told I would have to buy all of the engine bay loom, $2300Aust. I declined his fine offer.
Replacement with normal auto quality cable seems straight forward and I think I will re route the wiring to avoid engine heat.
The strange thing is I never had any electrical gremlins before my little accident. There has been a couple of similar postings on the list in the last couple of days so an inspection in that area may save you an enginebay fire!
The cables to the starter motor are almost as bad and will be replaced too. I can pinch the insulation off.

Graham Bates
'82 928s Euro anniversary model, slowly recovering.


I don't know how you are going to wrap the repair, but in a similar repair I used 3M woven fiberglass high temp tape, followed by some really neat "self bonding silicone tape" which is good to 500F.

If you've never seen this silicone tape, you should take a look at it. It self vulcanizes to itself and really does a good job sealing and protecting against oil and water. I bought a 1 in by 36 ft roll from Pegasus (#3929) for $9.99.

*Paul Scott

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