Harness Making Tips & Tricks

[ArdWrknTrk]

So for re-wrapping the existing harness, do you guys wrap with Tesa and then the braided split loom or just the Tesa?

I was saying to Gary that sometimes I like to wrap it candycan like, to get it all to lay into the corners and such before sliding the braided sheath over it.

If I were doing missile or satellite harnesses I'd do like the Scatch.

But my truck is not something that is going to fall out of the sky, or lose a war.

I also do not find huge reward in wiring.

I try to do a very good job, but it's not my passion for perfection.

[Gary Lewis]

I agree with the above about tesa tape. We wrap harnesses at 50% overlap. I prefer the braided loom to split loom for a couple reasons. Split loom has to be sized perfectly. Braided loom does not you can shrink it down as necessary. Braided loom is also easier to make break outs with, more flexible, and won't start cracking on you down the road the way the solid split loom will.

For setting up wire runs I prefer what we call temp ties. Panduit and other companies make them. They are a zip tie with a little tab that releases the lock so you can reuse them.

For final wire bundling I prefer waxed string tie or "cobra" head zip ties that are installed with a panduit gun like the GTS-E.

I avoid vinyl electrical tape at all costs most anything you need electrical tape for you can use silicone tape. It vulcanizes to itself permanently there is no adhesive. You can use this to make strain reliefs, terminate sleeving, water protection, dust protection etc. It can also be used to wrap wire bundles in areas prone to chaffing, debris, heat etc (like tesa tape) but will stiffen the bundle a bit.

Ok, I'm trying to get down to specifics. I've found several braided looms:

• PET: This is good to 257 F.

• Nylon: I can't find a temp rating on this.

As for the cobra headed zip ties, are these they? If so, I haven't found the gun yet. Any suggestions?

Cobra ties are one brand of low profile zip tie I have seen used.

The way the head on normal zip ties sits is bulkier, it can lead to chaffing issues, the "teeth" area along the flat part is also against the wire, and a lot of times you get that sharp tail.

Panduit's version looks like this and when cut the tail is not exposed. Also the smooth side of the tie rests on the wire... no chaffing.

If you look up zip tie gun you can find some cheaper options in the $20-$75 that work with all kinds of zip ties. A panduit GTS zip tie gun probably runs about $150.

Most of these zip ties both panduit and the reusable one (tab release) can be found at Grainger.

https://www.grainger.com/category/electrical/electrical-supplies/wire-management-cable-organization/cable-ties

They make quick work of a harness but speed comes at a cost. I am lucky I can buy bulk left overs here from Boeing auctions for pennies. But, I'm more old school and prefer to use waxed string tie AKA lacing tape, AKA lacing cord. It's cheaper and I enjoy it. The flat kind is what you want. You can find this unwaxed a lot of times with leather stuff. You can also get high temp stuff that has nomex in it which is usually black or white with black dashes down the middle. The preferred method is to do a clove hitch around the bundle then secure that hitch with a square knot.

This is an example:

https://www.amazon.com/Lacing-Cord-Nylon-Black-Width/dp/B00UYD9E6O/ref=sr_1_4?keywords=Flat+waxed+lacing+cord&qid=1580765902&s=electronics&sr=1-4

On the braided loom I have been using PET it has an operating temp of 257 degrees but a melt temp of about 450 degrees.

Nylon usually runs -50ish to 300 F whether it is flat or round braid, expandable or not.

Scatch - Thanks for the explanation. Do the cobra-headed ties need a gun to tighten them? Or can I just do them by hand?

And that link to Grainger helps as it shows so many different kinds of ties.

As for the braided loom, looks like PET is the way to go then.

But I'm with Jim - I think the zip ties and Tesa tape will be adequate for what I'm doing.

Thanks, guys!

[Danny G]

I was saying to Gary that sometimes I like to wrap it candycan like, to get it all to lay into the corners and such before sliding the braided sheath over it.

If I were doing missile or satellite harnesses I'd do like the Scatch.

But my truck is not something that is going to fall out of the sky, or lose a war.

I also do not find huge reward in wiring.

I try to do a very good job, but it's not my passion for perfection.

Lol yea you are correct it can get to be a bit more than necessarily needed. I'm a creature of habit on wire runs and its what I'm comfortable with. If you look at your harnesses etc in the trucks now... they have lasted 30+ years in that configuration. It all depends on how "built" each person want their harness. I guess you could liken it to someone who goes unnecessarily crazy on a suspension or chroming out an engine bay etc.

[Gary Lewis]

Lol yea you are correct it can get to be a bit more than necessarily needed. I'm a creature of habit on wire runs and its what I'm comfortable with. If you look at your harnesses etc in the trucks now... they have lasted 30+ years in that configuration. It all depends on how "built" each person want their harness. I guess you could liken it to someone who goes unnecessarily crazy on a suspension or chroming out an engine bay etc.

Or someone who powder coats a transfer case?

[ArdWrknTrk]

Or someone who powder coats a transfer case?

...... every bit and bob, not just the case

[Danny G]

Or someone who powder coats a transfer case?

...... every bit and bob, not just the case

lol like door lock mechanisms and arm rest braces....

[85lebaront2]

Or someone who powder coats a transfer case?

...... every bit and bob, not just the case

lol like door lock mechanisms and arm rest braces....

If these will upload (I got them as small as I could) this is part of my current project car. I am using a 1989 dash in it, but, I have a very nice radio system that has as part of it's features, a top down equalization mode. It requires a Body Computer to tell it when the top is down, so after scaring one up and Pick-n-Pull, I found that it needs a bunch of inputs I didn't have.

This is the portion I have started on, steering column to dash and BCM connections. If everything works I will also have a remote keyless entry system.

Tape is friction tape as I have found it remains reasonably flexible while working on it and doesn't seem to unwrap like vinyl tape does.

[Gary Lewis]

If these will upload (I got them as small as I could) this is part of my current project car. I am using a 1989 dash in it, but, I have a very nice radio system that has as part of it's features, a top down equalization mode. It requires a Body Computer to tell it when the top is down, so after scaring one up and Pick-n-Pull, I found that it needs a bunch of inputs I didn't have.

This is the portion I have started on, steering column to dash and BCM connections. If everything works I will also have a remote keyless entry system.

Tape is friction tape as I have found it remains reasonably flexible while working on it and doesn't seem to unwrap like vinyl tape does.

Bill - You've done a lot of work to take that rat's nest to an organized harness. But do you plan to use any convolute or braid?

[ArdWrknTrk]

Bill - You've done a lot of work to take that rat's nest to an organized harness. But do you plan to use any convolute or braid?

I'm not Bill, but it seems to me that all of that is on the interior (as it is, in a konvertible)

Why on earth would you -scratch that- would any sane person put loom on harness that doesn't need any protection from abrasion, heat and mud?

I mean, if it's all trussed up -even with floss- and well secured, adding another layer is pointless and makes it that much more difficult to service.

[85lebaront2]

I'm not Bill, but it seems to me that all of that is on the interior (as it is, in a konvertible)

Why on earth would you -scratch that- would any sane person put loom on harness that doesn't need any protection from abrasion, heat and mud?

I mean, if it's all trussed up -even with floss- and well secured, adding another layer is pointless and makes it that much more difficult to service.

First, Jim, no one has ever accused me of being sane as far as some of this goes. The original harness on these cars was taped and a bit of it was in the split loom as it keeps it all in position. There are not too many retaining areas on these dash assemblies and the harness needs to be restrained during assembly. The dash is held in with 4 medium sized washer faced self tapping screws along the windshield base, 2 M6X1.0 bolts with captive washers and the area over the steering column has 2 M6X1.0 studs that pass through the lower metal reinforcement. The design is similar to the Bullnose in that it is a plastic assembly over a built up metal frame, main difference is all the metal is ends and lower section. The center is tied to the floor hump and the lower portions including the glove box attach there and to the cross piece. This dash came from a 1989 Lebaron Coupe that had an air bag, so a lot of the structure was for that.