Topic: 1968 San Jose GT 390 Fastback Wiring Harness Restoration

[bullitt68]

I just pulled out my wiring harnesses for the first time since removing them from the car and I am wondering if restoring them or replacing them is the way to go. The radio/8 track harness has been hacked up pretty bad. I think one of the door harnesses has been replaced. The rear wiring harness sheaths are falling apart. I thin that the engine bay harness has been reaped with electrical tape. The under dash harness looks to be in pretty good shape.

[67gtasanjose]

Underdash harness needs some repair work too but looks salvageable. If the under hood harness isn't too brittle it looks ok too. Taillight harness would take some work with new taillight sockets spliced in far enough back to be hidden under the weave. Rhode Island Harness can re-apply the weave, nothing aftermarket will look right so that might be a way to go. 8-track harness is reproduced. Door harnesses are also reproduced (Alloy Metal preferably) but they do not come with the locators so save your originals for parts. Convenience Control harness for 68's is not reproduced so you might need to rework yours, same with the Tilt-away harness.
Reproduction harnesses all have a trade-off in appearance so if possible, look for donor harnesses from other original cars for sections needed. You might be able to splice in reproduction ends for items such as the tailight ends (to get bright/shiny zinc dichromate finish) but I don't know where you would source those.

Hope this helps.

[bullitt68]

Underdash harness needs some repair work too but looks salvageable. If the under hood harness isn't too brittle it looks ok too. Taillight harness would take some work with new taillight sockets spliced in far enough back to be hidden under the weave. Rhode Island Harness can re-apply the weave, nothing aftermarket will look right so that might be a way to go. 8-track harness is reproduced. Convenience Control harness for 68's is not so you might need to rework yours, same with the Tilt-away harness.
Reproduction harnesses all have a trade-off in appearance so if possible, look for donor harnesses from other original cars for sections needed. You might be able to splice in reproduction ends for items such as the tailight ends (to get bright/shiny zinc dichromate finish) but I don't know where you would source those.

Hope this helps.

Thanks Richard. My under hood harness is pretty brittle compared too the rest. I think my convenience group harness is good. My tilt away system was missing when I got the car. I was planning to replace the 8 track harness. I was thinking of getting Rhode Island to restore the rear harnesses. I guess first I will try to clean them up and remove the tape and see how they look inside. Anything I should know about cleaning them, cleaning product etc

[67gtasanjose]

Thanks Richard. My under hood harness is pretty brittle compared too the rest. I think my convenience group harness is good. My tilt away harness was missing when I got the car. I was planning to replace the 8 track harness. I was thinking of getting Rhode Island to restore the rear harnesses. I guess first I will try to clean them up and remove the tape and see how they look inside. Anything I should know about cleaning them, cleaning product etc

No easy way to clean them, there are a few threads discussing what others have used but stay off the tracer stripes as much as possible...you will wipe them off. I think lanolin hand cleaner is a recommended product. Search "Lanolin hand"

Re-read my comments in edit above about reproduction door harnesses. You replied before my edit came up.

[bullitt68]

No easy way to clean them, there are a few threads discussing what others have used but stay off the tracer stripes as much as possible...you will wipe them off. I think lanolin hand cleaner is a recommended product. Search "Lanolin hand"

Re-read my comments in edit above about reproduction door harnesses. You replied before my edit came up.

Great thanks I just re read you edited comments now

[midlife]

No easy way to clean them, there are a few threads discussing what others have used but stay off the tracer stripes as much as possible...you will wipe them off. I think lanolin hand cleaner is a recommended product. Search "Lanolin hand"

Re-read my comments in edit above about reproduction door harnesses. You replied before my edit came up.

I see this comment about staying away from tracer stripes.  For 12 years now, I have been cleaning with lacquer thinner on a rag which works quite well.  The only time I've seen wire colors be wiped away is on some fuel lines in the tail-light harness and fusible links near the starter solenoid.  In these cases, the wires have been painted due to the non-standard insulation (rubber-like substance).  Very rarely I've seen standard PVC wires also painted because the underlying colors were wrong for that application (ran out of that specific wire color during manufacturing?).  Again, very rare circumstances where wire colors get removed with cleaning.
Obviously, don't soak wires in any liquid or solvent.  You can wipe vigorously with any mild to moderate (up to lacquer thinner) cleaning agent without fear of losing colors.  The colors in the wires were embedded in the plastic at the time of wire manufacture and are not painted.  That's not so true today with modern replacement wires, as it is cheaper to paint the wires vice colorizing the insulation during manufacture.

[67gtasanjose]

I see this comment about staying away from tracer stripes.  For 12 years now, I have been cleaning with lacquer thinner on a rag which works quite well.  The only time I've seen wire colors be wiped away is on some fuel lines in the tail-light harness and fusible links near the starter solenoid.  In these cases, the wires have been painted due to the non-standard insulation (rubber-like substance).  Very rarely I've seen standard PVC wires also painted because the underlying colors were wrong for that application (ran out of that specific wire color during manufacturing?).  Again, very rare circumstances where wire colors get removed with cleaning.
Obviously, don't soak wires in any liquid or solvent.  You can wipe vigorously with any mild to moderate (up to lacquer thinner) cleaning agent without fear of losing colors.  The colors in the wires were embedded in the plastic at the time of wire manufacture and are not painted.  That's not so true today with modern replacement wires, as it is cheaper to paint the wires vice colorizing the insulation during manufacture.

Err on the side of caution then would be perhaps a better way to state it because lacquer thinner WAS used in cleaning some my harnesses and I did get some tracer paint wash off (rather easily) and others no issue (like you stated) but which is worse? I know there are essentially two grades of lacquer thinners on the market, one being a bit stronger than the other. I only buy the "good stuff" because it works where the other type does not.

[Coralsnake]

My advice, as a wiring salesman, replace them all. 😉

The red GT500 KR owner will support me on that.

Especially,  in light of the fact 5/8 photos are with splices already, you have stated the others are brittle. You can chase these for years or do it once. 

Lets get that tilt working also, instead of bypassing the wires!

[jwc66k]

I see this comment about staying away from tracer stripes.  For 12 years now, I have been cleaning with lacquer thinner on a rag which works quite well.  The only time I've seen wire colors be wiped away is on some fuel lines in the tail-light harness and fusible links near the starter solenoid. 

A big DON'T is use "Goof-Off" to clean wires. I recommended Goof-Off to a friend to remove road tar from his bumpers (64 1/2 Dearborn Convertible). He used it on some dirty wires in the engine compartment. It removed the wire tracers, but the wires were "clean". We did find NOS replacements.
Jim

[67gta289]

Xylene will clean nicely and leave the stripes alone.  PPE, gloves in this case, is tricky. Xylene eats latex and nomex gloves. 

[bullitt68]

I see this comment about staying away from tracer stripes.  For 12 years now, I have been cleaning with lacquer thinner on a rag which works quite well.  The only time I've seen wire colors be wiped away is on some fuel lines in the tail-light harness and fusible links near the starter solenoid.  In these cases, the wires have been painted due to the non-standard insulation (rubber-like substance).  Very rarely I've seen standard PVC wires also painted because the underlying colors were wrong for that application (ran out of that specific wire color during manufacturing?).  Again, very rare circumstances where wire colors get removed with cleaning.
Obviously, don't soak wires in any liquid or solvent.  You can wipe vigorously with any mild to moderate (up to lacquer thinner) cleaning agent without fear of losing colors.  The colors in the wires were embedded in the plastic at the time of wire manufacture and are not painted.  That's not so true today with modern replacement wires, as it is cheaper to paint the wires vice colorizing the insulation during manufacture.

Thanks Randy appreciate the information

[Coralsnake]

I dont recognize the fifth photo, do you recall what that underdash harness plugged into? Its the one with the relay in the center of the photo?

[Coralsnake]

I donr recognize the fifth photo, do you recall what that underdash harness plugged into? The is the one with the relay in the center of the photo

[bullitt68]

I dont recognize the fifth photo, do you recall what that underdash harness plugged into?

I didn't recall off hand what it is either. I will take a look as I labeled the bag it is in. I suspect that it is an under dash sub harness

[Coralsnake]

Probably convienence control panel?