Wire Harness Insulation Abrasion Fix

[2jmotorsports]

I am in the process of inspecting my 83 SC's engine wire harness. The tape has unraveled in several areas, probably due to prolonged exposure to engine oil in a filthy engine compartment.

Besides being dirty, there are no big surprises so far. I did find some small areas where the insulation has been abraded from about 3-4 individual wires like this:



There are no broken wire strands or connections thankfully. After cleaning, what is the best way to touch up these individual bare spots before re-taping the whole harness? These spots are all midway in the harness branches. Have not tried to de-pin any connectors. If de-pinning is not practical I would have to cut, solder, shrink wrap, but these are so minor it almost seems better to touch up the insulation with something then re-tape.

Thanks in advance.

[timmy2]

Do it right. Replace any wires that are not fully pliable or have signs of damage.
Or this could be you....
You are an engineer (mech) you should know there are no shortcuts to doing it right.

[dlagerstrom]

This potential issue is corrosion. Moisture gets in where the insulation has been compromised. Make sure the copper is not stiff. As a short term measure before you replace the wire, you can use liquid electrical tape. Basically a glue that acts like electric tape.

[Tea Tray]

I would consider stripping the harness jacket back, clean wires with solvent carefully, and wrap carefully wth 3M 33+ or 88 electrical tape, overlapping 50%. Repair harness and enjoy. Many harnesses in the day used taped junctions.
If you are wicked worried, cut, splice, retape the harness. Marine grade heat shrink butt splices work well...they have a melty goo that keeps that pesky oxygen away from the connection. Oh, take the cheap crimp plier/strippers you have and give them to someone you don’t like. Klein makes real good crimpers.

[2jmotorsports]

Thanks everyone for the input. I will assess each trouble spot/wire carefully and determine if the copper is flexible enough to repair or just replace the wire.

Dennis, no shortcuts! I do believe this harness is a good candidate for repair instead of replace but if something seems sketchy I will report back.

[timmy2]

The yellow one that is abraded in the photo runs from the TTS to the CSV.
Energized every time you start the engine. De-energized when running.
Bend every wire to test flexibility and insulation integrity.
35 years of extreme heat cycles has an effect.

[pmax]

Is the abrasion from heat damage or the zip tie like the one in the pic ?

Someone has played with the harness prior.

[2jmotorsports]

pmax, those zip ties are all temporarily put in by me to keep the "branches" the correct length. There are a bunch all over the harness that I will remove as I re-tape.

[SalParadise]

I would not use 3M 88 or anything of the sort on re-wrapping. You need to get real abrasion and heat resistant tape - and there is only one brand - Tesa 50126. This is the best tape for wiring harnesses - it doesn't have all the goo that 3M tape has and is made for engine wiring harnesses.

[timmy2]

ETN-1000E harness tape. Very similar to OEM. eBay

[pmax]

Originally Posted by 2jmotorsports

pmax, those zip ties are all temporarily put in by me to keep the "branches" the correct length. There are a bunch all over the harness that I will remove as I re-tape.

Ah, OK. Then I would wonder what caused the damage to just those 2 (?) wires in the bundle.

Originally Posted by SalParadise

I would not use 3M 88 or anything of the sort on re-wrapping. You need to get real abrasion and heat resistant tape - and there is only one brand - Tesa 50126. This is the best tape for wiring harnesses - it doesn't have all the goo that 3M tape has and is made for engine wiring harnesses.

I used Tesa 51036 which seems like the same product. They are both fabric based (not PVC). It's also rated to 150C and looked fine to me.

https://www.amazon.com/gp/product/B01I2MLN2Q

[3rd_gear_Ted]

If the pin can be removed from connector and the wire snaked out of harness, a length of heat shrink tube can be slid into position over the abraded wire.

If wire ends can't be accessed, "Glyptol" (by G.E.) can be layered onto exposed wiring with a small paint brush, then taped

[SalParadise]

Originally Posted by pmax

I used Tesa 51036 which seems like the same product. They are both fabric based (not PVC). It's also rated to 150C and looked fine to me.

https://www.amazon.com/gp/product/B01I2MLN2Q

Tesa 51036 is not the same as 51026, however 51036 is somewhat better because it has better (2X) adhesive than 026. I have both and have used both, but 036 sticks better.