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Discussion Starter · #1 ·
Dumb question... But I have to ask, only because I don't know...

What purpose does the ground strap going from the firewall to the hood serve?

Mine disintegrated last year sometime and I never replaced it.
Seems to have not created any problems so far.

Is it only there for grounding the factory engine compartment light under the hood, which is also not there any longer?

Maybe there is some other reason for its existence, but I can't figure out what that would be...
 

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The light has its own ground wire

The hood is grounded to reduce stray interference electrical noise from engine compartment (particularly ignition noise) that might effect radios and cb radios and perhaps communication bus


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The light has its own ground wire

The hood is grounded to reduce stray interference electrical noise from engine compartment (particularly ignition noise) that might effect radios and cb radios and perhaps communication bus
X2 exactly.
 

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Discussion Starter · #4 ·
Thanks!
Then, I guess I'll replace it at some point...
So far, no noticeable interference with the radio (aftermarket), I don't yet have a CB installed and all systems seem to be running OK.
 

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It's not necessarily just for your own radio. Imagine a couple thousand cars running around town putting out rf interference... now imagine if we had a system like hood bonding that could help reduce some of that interference on each of the vehicle, and what that would do for the entire town.
 

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I would think it would be to ensure that the hood is at the same electrical potential as the rest of the vehicle to cut down on cathodic corrosion.
 

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Why would there be any if it was electrically isolated from the rest of the body
And if it was not isolated it would already be grounded


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Why would there be any if it was electrically isolated from the rest of the body
And if it was not isolated it would already be grounded
Painted hinges would not guarantee it to be isolated or to have a good ground as not to create an electrical potential. Adding a ground strap it a much more reliable way to get the same potential throughout the jeep.
If is hood is acting as a Faraday shield why would there be a path to the vehicles electrical system VIA a ground strap?
 

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Because the vehicle uses a chassis ground for its electrical system
The chassis and body are all at one potential, if the were not then the electronics would have a hard time, there would be floating grounds everywhere.
 

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Yep chassis ground is body ground and my first post still makes sense and yours does not

But if being contrary suits you I let you find another playmate




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Yep chassis ground is body ground and my first post still makes sense and yours does not
I am not playing with anybody, your and others who say that the Hood is supposed to cut down on electrical noise, send it to the rest of the body through the ground strap makes no technical sense, period.
If that were the case, what happens to the "noise" that is headed out the sides, front and bottom of the engine compartment, or is the noise directed by some strange transponder under the hood. If the "noise" was so bad that it would interfere with CB's and radios what the hell do you think the "noise" would do to all the unshielded sensor wiring, how is the noise prevented from being picked up by any open ground source in the engine compartment (like the engine itself).
The hood strap being there for electrical noise being broadcast from the ignition system is pretty damn bogus, I don't care how much crap anyone knows about TJ's, that assertion makes as much sense as the holes in the body being used to lift an assembled body onto the frame during the vehicles assembly process.
 

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It's because electronic emissions are straight line, left to themselves they don't bend. Your radio antenna is above the hood, you need the strap to suppress noise in the radio.

As far as cathodic corrosion, that's only between dissimilar metals. Steel hood to steel firewall don't react.
 

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It's because electronic emissions are straight line, left to themselves they don't bend. Your radio antenna is above the hood, you need the strap to suppress noise in the radio.
Um, no

As far as cathodic corrosion, that's only between dissimilar metals. Steel hood to steel firewall don't react.
Again, no if there is a potential between two metals, meaning there is also the possibility of current, then one of the metals can become sacrificial and since the hood has less mass than the tub, guess what it becomes sacrificial.
 

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My vote is for the guy named "Sparky" with the electronic schematic for an avatar.
 
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The electrolytic corrosion theory is groundless

If the hood was grounded the strap would be non functional and if it was isolated there would be no
Conduction to produce the corrosion so it makes zero sense but hey everyone can have whatever opinion they want to


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Too bad physics ain’t based on a popularity vote
NO SHIT, if your "physics" held any water then either GM did a damn good job of sealing in all electronic noise on a Vette or it must be ****ing with everything it passes since it only has fiberglass bonnet.
It is not an opinion, go get yourself a book and read it, you make no "physics" at all go learn what you are talking about.

If the hood had a solid ground then there would be no need for a strap to take care of these mythical, oh so powerful electrical noise that these TJ's must produce. Same as if the hood was totally isolated, then again no need for a ground strap.
The hood hinges do not guarantee a good contact ground (just go look at them) hence the floating ground, causing a potential between the metal of the hood and metal of the body.

And why is there not any "Shielding" on the bottom of the engine compartment, how about the sides,

Though you were done playing, next time learn the game instead of just following along.
 

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Arrogance in face of being wrong how special you must think you are
Whatever dude, go get a book and lean something
 
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