strange wiring

[harmony]

Back in the winter when I was updating the wiring under the hood on my 48 Chrysler Windsor, I came across a strange wiring set up.  The hot wire between the coil and the regulator was sheathed by the ground wire that goes from the regulator mounting bolt to the coil mounting bolt.  So as the pictures show the ground wire is a multi-strand hollow woven type.  

So my question is , What's the point? My thinking is lets keep ground and hot wires far apart as possible when possible.  Plus the time factor of feeding the hot wire through the ground wire, before fastening the eye ends on it, seems time consuming.  

Has anyone seen this before or might have a logical explanation for why it was done? 

[greg g]

I can see the rational for the ground wire from the body to the engine as it provides a solid ground for stuff attached to the body sheet metal.  As for running the powered wire through it, I haven't a clue as it seems to be getting for a direct short for the ignition.

[DonaldSmith]

Maybe it's an early version of coax cable - prevent radio static. 

[Sniper]

Typically RF noise suppression.  Usually to keep the hot wire from [picking up stray interference that might induce odd behavior in the part being fed.

 

Not something I see in automotive wiring before computers.

[junkers72]

My 47 Desoto has it . I didn’t want to re invent the wheel so when I rewired it under the hood I replaced the wire going through the ground without too much hassle. 

[harmony]

I gave some thought about radio static, but I decided to keep the wires seperate when I replaced them and when I went for my first drive after, I didn't notice any static on the radio.

[harmony]

1 hour ago, junkers72 said:

My 47 Desoto has it . I didn’t want to re invent the wheel so when I rewired it under the hood I replaced the wire going through the ground without too much hassle. 

Then perhaps it's safe to say it came out of the factory that way. That's one job, I wouldn't want at the assembly plant.

[Eneto-55]

I imagine the ground was woven over the other wire during manufacturing.  Could it be to protect against hot wiring the engine?  (Might be a dumb comment, as I no longer remember which wires you would need to access to do that. Oh well.  Everybody says something stupid sometimes.)

Edited April 3, 2021 by Eneto-55

[harmony]

22 minutes ago, Eneto-55 said:

I imagine the ground was woven over the other wire during manufacturing.  Could it be to protect against hot wiring the engine?  (Might be a dumb comment, as I no longer remember which wires you would need to access to do that. Oh well.  Everybody says something stupid sometimes.)

I think maybe it's the other way around.  This is just a guess, but maybe there would be a hollow rod that would slide into the centre of the braided ground wire, with a point on one end that would poke through the side of the ground wire at a specific length ( similar to a fid tool used in splicing eyes on the end of braided rope)  Then the hot wire would be fed through the hollow rod with a few inches on each end to spare, then the rod would be pulled out.  That braided ground strap was super flexible so I'm guessing someone would do that assembly by hand.  

[Eneto-55]

9 hours ago, harmony said:

I think maybe it's the other way around.  This is just a guess, but maybe there would be a hollow rod that would slide into the centre of the braided ground wire, with a point on one end that would poke through the side of the ground wire at a specific length ( similar to a fid tool used in splicing eyes on the end of braided rope)  Then the hot wire would be fed through the hollow rod with a few inches on each end to spare, then the rod would be pulled out.  That braided ground strap was super flexible so I'm guessing someone would do that assembly by hand.  

I went back and looked at the photo again, and the way that weave looks, it would not be difficult at all to push a wire through, depending, of course, on the distance you needed to go.  That kind of weave is like the "Chinese Finger traps", or the deal that some electricians will use to pull cables.  You compress the hollow weave longitudinally and the diameter becomes much larger.  I have fire resistant sheathing (and you can get it at places like Allied Electronics) that is made to put over wires that need to be protected.  

But as to the purpose for doing it in this case, well, maybe the impedance idea is the most likely.  (This is also the way Cat6 network cable is made, with a ground wire weave over the smaller insulated wires on the inside.)

[knuckleharley]

There is such a thing as wiring that isn't strange?

[MackTheFinger]

Pretty much has to be for noise suppression. Some electric guitars, particularly older Gibson Les Pauls; use similar wiring although in smaller gauge.

 

https://www.stewmac.com/electronics/components-and-parts/wires/shielded-push-back-wire-16-inches.html

[James_Douglas]

My 1947 Desoto Suburban has that as well. I don't use it as I use suppression core spark plug cables and I add body to block grounds in several places.

 

James

[chrysler1941]

Mine has it too.

As mentioned earlier it's a standard way suppressing high frequency, AM radio, still used today in transmitters and receivers.

From what I understand, these where fitted to cars with factory radio. They where used in combination with other grounding suppressors.