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Home » Public Forums » GMCnet » ELECTRICAL Ground Issue (Grounding)
ELECTRICAL Ground Issue [message #356338] Wed, 01 July 2020 21:48 Go to next message
Husker92592 is currently offline  Husker92592   
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Registered: August 2013
Location: Temecula ca
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So I am replacing the cables to the starter and the battery and I reconnect the ground and the small cable that runs to the passenger floor well in the engine bay up front gets hot and melts when the ground on the battery is connected.

Anyone have any thoughts?


1974 GMC Sequoia 26'
Re: ELECTRICAL Ground Issue [message #356340 is a reply to message #356338] Wed, 01 July 2020 22:15 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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I am not sure what small cable you are talking about that is burning.

There are suppose to be two cables connected to the Negative side of the battery. Ones is a heavy 4 ga. Black one that goes direct to the engine block and is attached to a bolt near the right side exhaust manifold. I believe its is really a stud and nut but could be wrong. The second cable attached to the negative battery terminal is a 14 ga. black wire that goes to the aluminum plate under the passenger side hood that the isolator and boost solenoid / relay are mounted on.

The positive of the battery should have a red 4 ga cable going to one side of the boost relay that is mounted on that aluminum plate.

If you can give us a better description on what wire is burning we will try to help. You obviously have a short somewhere.

Ken B.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: ELECTRICAL Ground Issue [message #356391 is a reply to message #356340] Fri, 03 July 2020 23:05 Go to previous messageGo to next message
Husker92592 is currently offline  Husker92592   
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Registered: August 2013
Location: Temecula ca
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Ken
Seems to be the 14 ga wore that attaches to the coach with a bolt on the back side of the glove box
Grant


1974 GMC Sequoia 26'
Re: ELECTRICAL Ground Issue [message #356393 is a reply to message #356391] Sat, 04 July 2020 02:21 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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We may be talking about the same thing. When you say "back of the glove box", are you seeing it attached from looking inside of the glove box door, or are you seeing it by opening the passenger side outside hood and looking straight ahead, and a little below eye level at a piece of aluminum plate?

Which wire is burning?


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: ELECTRICAL Ground Issue [message #356402 is a reply to message #356338] Sat, 04 July 2020 13:22 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Skinny negative is doing the work of the heavy black one or trying to. Double check the heavy one to the block. Also there should be a flat braided one to body rear of engine. With a meter you can do voltage drop testing and find the resistance, but sounds like main ground connection from battery to block. Block is the home plate for grounding, called star ground. Could be a faulty new neg cable where they crimped over insulation? It’s 2020 gotta prove new stuff is actually good not defective.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] ELECTRICAL Ground Issue [message #356405 is a reply to message #356402] Sat, 04 July 2020 13:33 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Like John mentioned, the grounding straps are very important.
The Majority of the mechanics never connect the ground , so you end up
doing it yourself.

On Sat, Jul 4, 2020 at 11:23 AM John R. Lebetski via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Skinny negative is doing the work of the heavy black one or trying to.
> Double check the heavy one to the block. Also there should be a flat braided
> one to body rear of engine. With a meter you can do voltage drop testing
> and find the resistance, but sounds like main ground connection from
> battery to block. Block is the home plate for grounding, called star
> ground. Could be a faulty new neg cable where they crimped over
> insulation?
> It’s 2020 gotta prove new stuff is actually good not defective.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
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> Unsubscribe or Change List Options:
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: ELECTRICAL Ground Issue [message #356407 is a reply to message #356402] Sat, 04 July 2020 14:57 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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JohnL455 wrote on Sat, 04 July 2020 13:22
Skinny negative is doing the work of the heavy black one or trying to. Double check the heavy one to the block. Also there should be a flat braided one to body rear of engine. With a meter you can do voltage drop testing and find the resistance, but sounds like main ground connection from battery to block. Block is the home plate for grounding, called star ground. Could be a faulty new neg cable where they crimped over insulation? It’s 2020 gotta prove new stuff is actually good not defective.
John,
I still do not understand if that "skinny negative" wire is the one he is burning. Does it burn when starting the engine with a high current draw? I read that he hooks up the negative battery cable and it burns the wire. Which wire and under what operating conditions?

In a properly wired coach that "skinny negative" wire should not burn
even with the main "heavy negative" battery cable disconnected. This is because there in no other circuit wired back to the master ground (the engine) from the aluminum grounding plate behind the passenger side hood. So if that is what is happening, then he has wired himself a ground loop somewhere associated with that plate and it also needs to be cleared.

I suggest that we do not have an enough information at this point to make a good diagnosis.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] ELECTRICAL Ground Issue [message #356410 is a reply to message #356407] Sat, 04 July 2020 15:12 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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That's why I have stayed out of this thread. The guy is only giving us a
tiny bit of the picture to look at. You have already asked him two or three
times for more info. Cannot give him much help with what he has provided so
far. Hope he doesn't burn his coach to the lugnuts in the meantime..
Jim Hupy
Salem, Oregon

On Sat, Jul 4, 2020, 12:58 PM Ken Burton via Gmclist <
gmclist@list.gmcnet.org> wrote:

> JohnL455 wrote on Sat, 04 July 2020 13:22
>> Skinny negative is doing the work of the heavy black one or trying to.
> Double check the heavy one to the block. Also there should be a flat
>> braided one to body rear of engine. With a meter you can do voltage
> drop testing and find the resistance, but sounds like main ground connection
>> from battery to block. Block is the home plate for grounding, called
> star ground. Could be a faulty new neg cable where they crimped over
>> insulation? It’s 2020 gotta prove new stuff is actually good not
> defective.
>
> John,
> I still do not understand if that "skinny negative" wire is the one he is
> burning. Does it burn when starting the engine with a high current draw? I
> read that he hooks up the negative battery cable and it burns the wire.
> Which wire and under what operating conditions?
>
> In a properly wired coach that "skinny negative" wire should not burn
> even with the main "heavy negative" battery cable disconnected. This is
> because there in no other circuit wired back to the master ground (the
> engine) from the aluminum grounding plate behind the passenger side hood.
> So if that is what is happening, then he has wired himself a ground loop
> somewhere associated with that plate and it also needs to be cleared.
>
> I suggest that we do not have an enough information at this point to make
> a good diagnosis.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: ELECTRICAL Ground Issue [message #357708 is a reply to message #356338] Fri, 14 August 2020 12:20 Go to previous message
Husker92592 is currently offline  Husker92592   United States
Messages: 137
Registered: August 2013
Location: Temecula ca
Karma: -4
Senior Member
So I found the issue and that was the starting solenoid did not have any isolators so the positive was a direct ground issue. There are non metallic isolators that are on the studs of the start solinoid so I ordered a new on form JIMK. Seems the battery was grounding through the sol. to the body and the small black wire that attaches to the negative ground side melted. Crisis repaired.

1974 GMC Sequoia 26'

[Updated on: Mon, 31 August 2020 09:47]

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