Wiring to Replace or Not, While the engine is out Options

[DennisV]

How problematic is the now 50 year old wiring? Some existing threads seem to suggest they're pretty vulnerable, yet I don't see wiring harness included on most "while the engine is out" todo lists.

Are there any that are consistently so troublesome that they should get proactively replaced even if they appear good? On the 914-6 it appears there are two for the engine bay (complete engine and alternator). That's $500 USD right there.

For reference, I'm not attempting a complete restoration. Just trying to get our car safely and reliably back on the road. The engine, transmission, and suspension components are out of the car. I've found a couple previous owner wiring additions, but they have been easy to remove.

My impression has been that if the wiring, insulation and connectors look good they probably are good. It's not like the copper wears out. Perhaps this is naive.

P.S. New plug wires are already obtained. I have no intention of removing the main harness.

[johnorm]

As others have noted, check for wires with bad connections, missing insulation and signs of overheating.

Bad grounds are the culprit for many unexplained electrical issues. Ensure that the common ground terminals plus the ground straps for the engine and transmission are all in good shape and that the contact surfaces are clean.

Typically the alternator harness, which is inexpensive to build or buy, is one to be carefully inspected for signs of deterioration and overheating. The other wires I would be concerned with are the yellow wire from the ignition to the relay board in the back (as mentioned by others) and the two red, heavy gauge, wires that run from the battery to the ignition switch (terminal 30) and the fuse box (Fuse 11, power side).