Over grounded?

MJ'sBlkBII · Apr 3, 2009

I think I may have found the start of my wiring mishap. I found a battery ground cable with terminal still attached sitting on the wheel well between the battery tray and air box. I traced it to a retainer on the frame then to a bolt on the block. Obviously this is the original way the ground was supposed to be run. The current negative cable is run to a bolt directly to the frame. When I found this cable I pulled it down to be contemplated. I decided this may be part of the issue with the block not being properly grounded, so I clipped the terminal off and bolted it to the frame. After this is when I found the smoke inside the cab.
My questions are: 1- should I remove the frame to block cable entirely since it did run with out it, 2- connect this frame to block cable to the battery to frame location for a possably very good ground, or 3- just run the current battery cable straight to the block and no longer to the frame? Also, could this scenario of connecting the block to frame instead of battery even be a possable culprit to the fried dash wiring? Would this explain the fried ground wire under the dash?
Thanks for any insight, MJ

RobbieD · Apr 3, 2009

Without seeing what you're dealing with, I can't give an opinion on why you had something smoke when you reconnected the cable you found. It does sound like the original ground, though, as it runs through a "retainer". Was this retainer insulated, or was the cable's copper conductor crimped into it, making a connection?

Regardless, you never know what a previous owner did, or had done. It kinda sounds like you came across the remnants of past problems, or a past hack job. If that "retainer" was insulated, your mystery wire may have even been an old starter cable (yikes!).

To answer your question, the engine, body and frame should be grounded, or directly connected, to the vehicle's battery (-) Negative post. And there are multiple ways to do this, depending largely if you buy an OEM or direct-replacement cable; or, if you make up the ground cables from aftermarket sources. The end goal, is the least possible electrical resistance between the engine, body, frame, and the battery's Negative post.

A good typical aftermarket arrangement would be universal 2-lead ground cable and a heavy jumper. First lead: battery Negative to a bolt on frame, and the jumper also on the same bolt and then to the block. Second lead: battery Negative to the body.

Hope this helps, and good luck with it.

MJ'sBlkBII · Apr 3, 2009

I belive the retainer was insolated (to much oil to tell). You should see the pics of the engine. :shok:

The cable should've been the ground from battery. It just hard mounts to the side of the block. The thing that worried me was the sparks from it before I bolted it as it was just touching the frame. The current cable has the battery cable and the other one to the radiator support. I think there is one more but I can't be sure right off. The old cable in question is only the single cable with a preformed terminal on it.
Bolting it with the battery to frame cable is what I am thinking I might try next.
You know, I don't mind gremlins so much but when it could roast an entire harness... :annoyed:

MJ

Ozwynn · Apr 3, 2009

if you got sparks at the wire when you touched that wire to ground then that wire is hot. If I am misreading your post then I agree with the other answer, run a ground from the neg terminal of the battery to the block and the body/frame. if you are only grounded to the block then it is trying to ground then it is trying to ground through the U-joints.

I typically ground to the block, fender, and the frame with a 4 gauge wire or better.

you can never have enough ground

MJ'sBlkBII · Apr 3, 2009

How can a wire run from the block to the frame be hot?! The current negative battery cable is currently grounded at the frame, with a smaller gauge wire to the radiator support. Like I said, it did run before in this fashion, with this new found wire not connected to anything but the block on one end. Oh, and it only sparked when attempting to start motor. Otherwise it did nothing.
So just for clerafication, the idea is to try connecting the block ground with the current negative battery cable merging the 2 at the frame?
Thanks for the help so far guys, MJ

Ozwynn · Apr 3, 2009

I am lost, the wire goes from the block to the frame? and it only sparks when you try to start it? where on the block does it come from ........ that sounds like a starter cable. Ground wires do not spark, only hot wires spark when they touch a ground source. that wire is hot some how or it is not what you think it is.

RobbieD · Apr 4, 2009

It is tough trying to figure out what you're dealing with there. Can you get us some pictures posted?

"you can never have enough ground"- amen to that, BDAB.

MJ'sBlkBII · Apr 5, 2009

BDAB said:
I am lost, the wire goes from the block to the frame? and it only sparks when you try to start it? where on the block does it come from ........ that sounds like a starter cable. Ground wires do not spark, only hot wires spark when they touch a ground source. that wire is hot some how or it is not what you think it is.

Lost is where I am too. I know all this this is why I am so :icon_confused:

. I am possative it is not the starter wire. I removed it myself when I did the tranny swap and 4.0 starter. Also, the starter wire shouldn't have a battery terminal mount premolded onto it...I would hope. :icon_rofl:

The cable bolts to the side of the block with nothing else.
I will post some pics when I get home on the 10th. My wife has said I am working on her car first and before all, and not deveating untill it's done.

RobbieD · Apr 5, 2009

Well, maybe taking a break from it is a good thing. Dive back into it with a fresh mind, and good luck.

MJ'sBlkBII · Apr 7, 2009

I'm a truck driver so I've had the last 2 weeks away. It's getting close to home time so I posted this for the ideas. Now I have to go down to Austin to help my wifes friend with her car instead of working on mine like I wanted. :annoyed:

What are you gonna do, right. I'll have about 3 days at home, so I'm figuring a day on my wifes car, a day on her frinds, then I can get to the BII and post the pics and figure out at least the dash wiring. Should be enough time for that. We'll see.

calypso93 · Apr 8, 2009

Not familiar with 88's but, the "sparking ground wire" may be a better ground than other. It conducts more current when your starting the truck, and since it conducts more, you'll get a spark. Even tho cables seem like zero resistance, when you draw 100+ amps thru it, you'll see a voltage drop. I think your extra cable is acting like a better ground.

AllanD · Apr 14, 2009

a Ground wire most certainly will spark if it's poorly connected and the OTHER ground wire is also poorly connected.

Say the loose one is carrying part of the load that the
other "connected" (but corroded) wire SHOULD be carrying.

"too many grounds" only wastes the wire used.

Disconnect ALL grounds, clean them ((with a wire brush)
smear them liberally with never seeze and reassemble.

If you have corroded grounds the current WILL follow the path
of least resistance and that can trace out some strange paths indeed....

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