TR4/4A Wiring Harness

[bammons]

I will soon be installing my wiring harness in my 65 TR4A. I have it laid out on the floor and upon inspecting it it seems to be in decent shape. It's last real use would date to about 1980. Most of the tape is there and end connectors are there. The car is being fully frame-up restored by me. I will have a 40 amp altenator but that should not be a problem I think. Am I making a mistake using the old harness? Is there anything I should do to the harness while it is out? Bruce

 

[Sarastro]

As long as the insulation is good--not dry, cracked, or burned--there is no reason not to reuse a harness. You might need to replace the bullet connectors, if you are continuing to use them. Better is to use some other kind of automotive connector; check Amazon.

If the wires are tarnished and you can't solder to them to replace connectors, dip the stripped end of the wire into a little dilute muriatic acid (or any other acid, for that matter; lemon juice might work) and then, when it's bright, dip it into some ammonia to neutralize the acid.

 

[bammons]

Ok that is what I was thinking but I know some have opinions about not reusing the harness. The bullet connectors seem to be good so I think maybe I will just use some emery paper or something to freshen them up. Any additional wires that I should add that I might regret not adding while it is out?

 

[Sarastro]

Well, I'm an electrical engineer, so I think I have some insight on this matter. It's been my observation that a lot of perfectly good harnesses are replaced unnecessarily, probably because the owner thought that there would have to be something wrong with them after a mere half-century or so.

I try to avoid using abrasives like sand or emery paper on connectors, because it takes off the surface finish (and there usually is one, even if it doesn't look like it.) My favorite de-tarnishing tool is a pencil eraser. It has just enough abrasive to take off tarnish without removing the surface finish. If that doesn't work, then you can step up to something a little more aggressive. Save the emery paper for a last resort.

I kept the old harness when I restored my TR4A. I did replace the bullet connectors, however, with Molex ones and replaced all the spade connectors with new ones. > Body electrics <

 

[bammons]

OK Steve I did not know that about the finish on the connectors so I will be careful on that. Not familiar with "Molex" so I will look at that as well. Thanks Bruce

 

[bammons]

This is the headlight wire (brown/blue) and obviously had a fuse added for what purpose I don't know. But the wire that attaches to the other end of the fuse is white (pinkish/white). Why would that be? Bruce

 

[Sarastro]

Yeah, there's no limit to the weird things that POs do, and if you try to figure out what they were thinking, you'll probably go nuts. Best just to set things up the way you want it, return it to stock or make sensible modifications (say, more fuses and relays) and not worry about it beyond that.