Big 3 and Dual Battery Kits

[Caman96]

I think it was on this forum somewhere or maybe another and it was pointed out that these grounds were setup in specific zones and changing locations was not a good idea.

 

[PlayingWithTBI]

I think it was on this forum somewhere or maybe another and it was pointed out that these grounds were setup in specific zones and changing locations was not a good idea.

yeah, I remember something about that but, IMO there needs to be a big ground from the block to the battery for the starter load. Then a good path from the block to the firewall for sensors, outputs, etc. The Vortec has the fuse block and PCM under the hood where TBI's are inside, so there's a difference in paths there too.

 

[shovelbill]

yeah, I remember something about that but, IMO there needs to be a big ground from the block to the battery for the starter load. Then a good path from the block to the firewall for sensors, outputs, etc. The Vortec has the fuse block and PCM under the hood where TBI's are inside, so there's a difference in paths there too.

On our Harleys, some of us do a redundant ground from the frame to the battery as you described. The electric gremlins that rear their heads typically go away, especially in the starting circuit on the older bikes...We increase the wire gauge for that too.

The rubber-mounted bikes have a similar woven ground strap under the bike that rots away. Nobody seems to know this exists either, lol.

PS...Most pre-2000 Harleys have their engines rigidly mounted/bolted to the frame.

 

[Caman96]

Maybe this is where I saw why it’s important to keep original ground paths: https://www.gmt400.com/threads/truck-is-acting-crazy.58709/page-9
I happen to agree with @thinger2 and
@1998_K1500_Sub on this subject.
This is one of @thinger2 posts in that thread.
“
Basically, grounds need to stay attached the the same "ground plane" as they were originally.
In other words, the same chunk of cast iron in your case.
If you move that ground off of the head to the block.
That ground now has to go through the head gasket.
It wont do that. It will ground to the shortest path.
The only way it can achieve that original grounding is through the head bolts.
It will ground to block instead.
The same thing happens if you move a ground from the intake to the block or the head.
The intake gasket is now in the way.
The problem people run into is that they do a continuaty test on the ground and get a tone out of the voltmeter and think its all good.
Each ground serves a specific set of paths.
When you move a ground to a different plane, you change that"path"
That path will be the shortest most direct.
And it will go through the easiest most conductive material.
Which can end up being the main bearings.
Bad or improper or missing grounds can also eat the bearings out of your transmission.
They are grounded in those planes for a reason.
We see this all the friggen time in the commercial boat world.
70 year old steel hull that is paper thin in 2 years because somebody moved a ground so it was easier to get at.
Knucleheads who paint over the hull zincs on wood boats and next year the bronze through hull valves turn to mush.
The best one was a "Engineer" who managed intermittant short a 480 volt gen pack to the prop shaft.
We just kept going slower and slower per rpm.
Then it shook like hell
Disimiliar metals and errant voltage ate the prop down a little three blade nub.
When that had nothing left to give the 6 inch diameter 22 foot long prop shaft turned into a noodle.
A warped noodle that ripped the cutlass bearing to shreds and broke the twin disk reduction gear and ripped it out of the bottom of the boat.
That problem, that electrolysis took a while to get that bad.
Probably a couple of years in the salt water.
But the all is well to the Mayday was about 45 minutes.
And dont try to chuck all of your coke and weed over the side while you are in a friggen gumby suit.
No thumbs. That **** will blow back on you and now you have to go for a swim before the coast guard shows up.
And fer ***** sake dont use a wood pipe no matter how cool it looks.
Wood floats, brass sinks”.

 

[Erik the Awful]

I think the tl;dr on ground planes is "don't daisy chain your grounds".

If you ground your body to the transmission, the transmission to the engine, the engine to the frame, and the frame to the battery, you could have trouble. The frame is a safe collection point for grounds, but I do like running a ground directly from the battery to the engine as well.

 

[Caman96]

I think the tl;dr on ground planes is "don't daisy chain your grounds".

If you ground your body to the transmission, the transmission to the engine, the engine to the frame, and the frame to the battery, you could have trouble. The frame is a safe collection point for grounds, but I do like running a ground directly from the battery to the engine as well.

The factory setup on my 96 has a ground direct from battery to front lower block. That is part of Big 3 kit. But, also, factory setup has a ground strap from rear head directly to frame.
Seems like there’s many different opinions on grounding routes. Who am I to say what’s better or worse, so by default I will follow original ground paths.

 

[PlayingWithTBI]

In the thoughts of gaskets getting in the way of a ground, how about all of the bolts holding the intake manifold and heads in place?

 

[Caman96]

In the thoughts of gaskets getting in the way of a ground, how about all of the bolts holding the intake manifold and heads in place?

I thought that too, but still in the end my truck does have a dedicated ground from battery to front block. For whatever reason GM also added the frame to head ground. Since there’s no evidence other than opinions, it just seems best to follow original plan.

 

[PlayingWithTBI]

Since there’s no evidence other than opinions, it just seems best to follow original plan.

And that's a good plan too

 

[mn_ski]

Can someone explain how this ground strap installs? Red line is original from frame, goes down a bit and under exhaust manifold, then goes up through a metal tube/wire manager and exits going up and bolting to head. The new 10 1/2” black ground strap is seen in picture and clearly doesn’t have the necessary length.

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I interpreted that location to be a Frame to body ground for the new cable. I left the frame to head connection and replaced the frame to body.

My engine block to frame connection is done up front by the water pump. Honestly at the time I didn't think about the difference between engine block and engine head grounds but it doesn't seem to hinder the operation of the truck doing it this way.

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