[72pontiac]

would you always replace the wiring harness during a driver style restoration or base it on condition

[Chris65LeMans]

Do you mean the engine harness or the under dash one? For either, I say base it on condition. Hard to believe a 56 y/o harness would still be in good condition - my under dash harness was all hacked up with old shade tree repairs. (Some done with duct tape.)

[Lemans64]

Agree with Chris, depends on condition. I took my dash harness out and went thru it before putting it back in.
Had some burnt wires, bad connectors and some bad spice points for aftermarket stuff. All ok now though.
Took a few nights to go thru it and had to find some twin lock connectors for firewall plugs. So probably worth the cost to replace it.

[72pontiac]

Guess it was one of those dumb questions.
If it was good it wouldn't need replaced. if it was bad it should be. It's correct that a 56 year old harness most likely is not going to be "good".

[Cardo]

I would replace the engine harness no matter what - 56 years of heat, elements, it can't be in fantastic shape. I consider that cheap insurance.

[JSchmitz]

It really varies tremendously in my experience. Some old wiring is still very pliable and corrosion free. Others crack if you touch a wire. My wiring harness seems pretty good on my '64 GTO. But I know I have about a volt drop across my fuse box. Also had to repair the hot lead going into the fuse box when a nut fell off and welded the diode bridge to the case! Lucky that I had a quick disconnect that day! I recently bought this for my car: https://www.americanautowire.com/sho...iac-gto-510188 I will be starting this soon.

[Chris65LeMans]

When buying new harnesses, don’t mess around - get the H &S

[Jack P.]

Change it, you will have corrosion in connectors and the fuse panel. The number one cause of fire in a classic car is a wiring short. They don't cost that much. I like M&H but a couple others are OEM as well.

[Chris65LeMans]

M and H. - that’s the one! (H & S is my plumber)