Brittle wire conduit on GM LS Engines

[Snagglefoot]

I believe most GM LS engines come with a plastic engine cover. If yours is 10 years old or older it’s a good idea to take off the cover and take a look underneath. Look at the main positive wire to the alternator plus a bundle of wire on the passenger side of the engine. They are supposed to be covered in a corrugated plastic conduit. My conduits very totally brittle and mostly crumbled away. I cleaned off the rest of it and put on new 1/2” corrugated split plastic conduit on it. Available at most auto store or super cheap on amazon. Here’s a few shots.

 

[Lubener]

There is wire loom available to handle the high heat encountered in the engine compartment. I believe it is identified with a stripe going through it. Standard loom will eventually get brittle in short time.

 

[Rhymingmechanic]

What is a good source for the high-temp variety? I have never found loom that resembles the factory material in stores. It's all a really thin, flexible plastic. Last time I used it, a portion melted against my intake manifold. I guess that wouldn't happen with plastic manifolds, though.

Snagglefoot's post shows that the factory loom clearly has durability problems as well, but in the longer term.

It must be "fun with plastics" week for Chevy trucks. I just changed a broken heater hose connecter on mine.

 

[Blinker]

The wire loom conduit GM used in the 2000’s was really cheap. I’ve owned several GM’s from this vintage and the wire loom conduit was cracked and crumbling away after just a couple of years.

The stuff the auto parts stores sell says not to install in the engine compartment because it’s flammable and the high heat causes it to melt to engine surfaces. Does anyone know where to buy good quality conduit? The conduit used in the 80’-90’s lasted much longer in my experience.

 

[wpod]

GM the hear tbreak of America their advertisements were so revealing. Plastic works great until it becomes brittle then breaks

 

[bdcardinal]

The wire loom conduit GM used in the 2000’s was really cheap. I’ve owned several GM’s from this vintage and the wire loom conduit was cracked and crumbling away after just a couple of years.

The stuff the auto parts stores sell says not to install in the engine compartment because it’s flammable and the high heat causes it to melt to engine surfaces. Does anyone know where to buy good quality conduit? The conduit used in the 80’-90’s lasted much longer in my experience.

I think DEI makes some, if anything a wrap to go around the conduit.

 

[Blinker]

I will look into that. Thank you!

I’ve engine gone to junk yards and taken the wire loom conduit from 80’s-90’s cars because it is much more durable and I could never find any aftermarket stuff that was any better.

 

[clinebarger]

Eagle Plastic Devices makes the best convoluted split loom I've ever used, I buy it from Mouser Electronics......PDF HERE (The flame retardant stuff)

For tape.....I use Tesa 51036, Outstanding tape!!!

 

[clinebarger]

GM switched suppliers in/around 2005, Before that.....The split loom held up quite well.

 

[brianl703]

What is a good source for the high-temp variety?

I've ordered electrical supplies from this company in the past:

https://www.delcity.net/store/Loom-&-Loom-Clamps/

 

[brianl703]

Also this one:

https://www.waytekwire.com/products/1467/Wire-Coverings-Protection/

 

[14Accent]

Is it really that big a deal to have crumbling loom? I see it day in and day out on cars of various ages, it never seems to present much of a problem. I'd be willing to bet that the wire's own insulation is at least as good if not better than corrugated looming. As far as I can tell, it's more about looks than function.

 

[TheLastWord]

Is it really that big a deal to have crumbling loom? I see it day in and day out on cars of various ages, it never seems to present much of a problem. I'd be willing to bet that the wire's own insulation is at least as good if not better than corrugated looming. As far as I can tell, it's more about looks than function.

Yes it is a big deal.

All sorts of electrical gremlins arise from crumbling loom.

The only thing worse is unconnected clips and fasteners left off by careless techs. So the wiring goes just anywhere.................. like high heat areas.

See it all the time. Some are hard to reconnect, the tabs break off, etc so just leave them loose

 

[frankd]

What Lubener said.

The high temp wire loom with the stripe lasts much longer and does not discolor.

This stuff looks and feels like factory high temp split loom. Notice how the edges are squared instead of rounded.

You can also find the same stuff on ebay.
https://www.cabletiesandmore.com/nylon-split-wire-loom-tubing

 

[clinebarger]

Is it really that big a deal to have crumbling loom? I see it day in and day out on cars of various ages, it never seems to present much of a problem. I'd be willing to bet that the wire's own insulation is at least as good if not better than corrugated looming. As far as I can tell, it's more about looks than function.

It can be.....Especially with engines that vibrate at a high frequency (Like Diesels), The split loom is just the first line of defense against abrasion & the harness/wire getting rubbed through.

 

[Blinker]

GM switched suppliers in/around 2005, Before that.....The split loom held up quite well.

Yes, this makes perfect to since. I still own a 2002 Camaro and the wire loom conduit is still in great shape. My 2006 and 2008 Pontiacs the conduit was brittle and in need of replacement after about 4 years.

 

[Blinker]

Eagle Plastic Devices makes the best convoluted split loom I've ever used, I buy it from Mouser Electronics......PDF HERE (The flame retardant stuff)

For tape.....I use Tesa 51036, Outstanding tape!!!

Thanks for the advice. I’m looking into this now!

 

[Snagglefoot]

I finished putting in the new looms. For the smaller bundle of wire, I had to put in on in sections as it had four wires branching off for the fuel injectors.PS, I’m not much for detailing the engine bay. We have five months of snow, slush and road grime ahead. The “before” shot is the lower one.

 

[Blinker]

It looks good.