Rebuilding your own wiring harness

[1968k10blue]

has anyone ever done this? if so, how hard would it be? I wouldnt think it would be too bad as long as you were careful to label everything and pay attention to what you are doing.

[19673ontree]

Ive redid the wire harness on 67 68 69 camaros I just take it all out all the wiring out from under the hood and also inside and untape it all replace any bad wires or ends I had like three or four old cut up wire harnesses to work with and once I had it all complete I would retape it all good and put it in the car mine worked perfect , I would say you can do it its fairly easy but takes a while ,

[LockDoc]

.. I have rebuilt quite a few of them. As long as you replace any brittle or cracked wires and clean both ends of the connectors really good you shouldn't have any problem. Do not use crimp connectors for splices, solder and heat shrink tube them. I also keep any old wire looms I come across for correct color coded wires. NAPA has most of the special wire ends you might need.

There a people on here that do not agree with this practice for various reasons and I hope they will chime in also.

LockDoc

[Rich916]

My original intent was to rebuild my engine harness. After pulling everything apart it wasn’t so much the wires but all the casing was becoming brittle and lost most of it pliability. Extreme heat and in some cases, extreme cold just toke its tole. For $88.00 I was able to purchase a new, year and engine specific harness.

IMO a better option.

[WIDESIDE72]

I have rebuilt under dash harnesses with new wire soldered in and covered with heat shrink where needed. LMC sell the plastic connector ends. Napa sells the wire terminals. I fixed a couple for myself and did a few to sell. I decided it wasnt worth my time to try and sell them.

[LockDoc]

Originally Posted by WIDESIDE72

I have rebuilt under dash harnesses with new wire soldered in and covered with heat shrink where needed. LMC sell the plastic connector ends. Napa sells the wire terminals. I fixed a couple for myself and did a few to sell. I decided it wasnt worth my time to try and sell them.

Yes, it takes a lot of time to do them. I only rebuild them for my own projects. I guess that is why the aftermarket looms are so pricey. There is no way to make them on a machine.

LockDoc

[burnin oil]

Classic parts is alot cheaper than Napa for the terminal ends. They are Packard 56 if you look for another source. I rebuilt both inner and outer harnesses in one evening including modifying the harness. The biggerst trick is to add the new wires and keep the original intact to maintain the shape. I added HEI, internal regulator alt, tach lead, and got rid of the junction blocks and used the starter terminal for this. Do yourself a favor and add a wire for an oil pressure gauge. This way you can add an aftermarket gauge without having a lone wire outside your new harness. You can always hide it under the tape or tuck it under the harness to hide it. New cinnectors can be gotten from many places or scavenged from other harnesses.

[1968k10blue]

That's part of my issue too, I already have everything wired up for HEI, tach, and internal alt. So I could always pull them off the old harness then put it on the new one. Also the other question I have is would it be better for me to buy the 69 and up harness since I have the lights in the bed or would that cause more problems than just wiring those up myself? This is if I decide to buy though.

[truckster]

Originally Posted by Rich916

My original intent was to rebuild my engine harness. After pulling everything apart it wasn’t so much the wires but all the casing was becoming brittle and lost most of it pliability. Extreme heat and in some cases, extreme cold just toke its tole. For $88.00 I was able to purchase a new, year and engine specific harness.

IMO a better option.

Where did you get a harness for $88? The ones I've looked at are a lot more expensive.

[leftybass209]

M&H has engine harnesses that can be had fairly cheap. However the more options added like HEI have a higher cost. That is not to be confused with the headlight harness that runs the alternator wiring, that runs a bit steeper in cost.

[imjeff]

I've had good luck getting the contacts that live inside the plugs and sockets at electronics stores. If you carefully take them apart and use new pieces with new wire (I like marine wire) you can minimize the number of splices. It takes more time, but it's therapy for the OCD.

[burnin oil]

Originally Posted by 1968k10blue

That's part of my issue too, I already have everything wired up for HEI, tach, and internal alt. So I could always pull them off the old harness then put it on the new one. Also the other question I have is would it be better for me to buy the 69 and up harness since I have the lights in the bed or would that cause more problems than just wiring those up myself? This is if I decide to buy though.

I dont remember the specifics but from memory it all ran to the back of the truck then branched off. I want to say the main harness ran to the rear crossmember then the rest of the tail wiring happened by the rear bumper on the drivers side. If that was the case it would be a simple splice. When it comes to wiring I trust mine over another. Seen way to many marginal wires in harnesses. I suffer from BIBs when it comes to wiring. Bigger is always better! Download the wiring schematic and have a look. When I customed mine I used the 72 diagram and one for a 76. Biggest part of the rewire was eliminating the regulator.

[danheit]

Just finished rebuilding the dash harness, and also had to completely rebuild the chassis and tail light harness. Couldn't wait for one to be shipped so I went to Advance Auto and purchased a trailer light wiring harness. Spent 30 bucks ended up with even the same color wires, Only thing I had to do was solder the old firewall connector onto one end of the harness. Still have nice clean and weather tight connections. Sure beats the $140 LMC wanted! Also, keep in mind, there's very few circuits here, and even if you pull everything apart and forget to label them, it's pretty easy to figure out. Just follow it from the fuse box to where it goes. There's only a heater plug, wipers, headlight switch, ignition and cluster. not much there to get lost on.