GMC ground points

[Ron Clark]

Gene Fisher...Are you still around?
(or anyone else with answers)

Have you any info on grounding points for the 12v system in a 78
Eleganza?
My furnace doesn't work and LED floor lights vary between not working,
and being really dim. Using clues from Emery and lots of kneeling by the
offending (or offensive!!!!) items, I noticed a 7.5v difference between
their ground and the ground of items that work properly.

thanks,
RonC

 

[Ken B]

I had the same problem twice on two different coaches. I never found exactly where those two grounds were attached. One was a 1978 and I do not
remember the year on the other one. I will tell you that the aluminum body is the master ground for the house system. So I gave up and ran another
ground wire to the aluminum body. Problem solved.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Ron Clark]

Thanks, Ken
what size wire did you use for the new ground wire? Did you connect it
directly to the battery negative, or to the neg. on the power converter
(charger), and where on the body?
ron

> I had the same problem twice on two different coaches. I never found
> exactly where those two grounds were attached. One was a 1978 and I
> do not
> remember the year on the other one. I will tell you that the
> aluminum body is the master ground for the house system. So I gave
> up and ran another
> ground wire to the aluminum body. Problem solved.
> --
> 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
>

 

[RF_Burns]

Size of wire for the replacement ground wire just depends on how much current the load consumes. I have lots of #12 and #14 black wire so that is what
I use. Its good for just about any house battery load, except an high power inverter.

I would just splice the new ground wire to the existing ground wire and run it to the nearest aluminum house frame. No need to run direct to the
battery ground. Put a star washer between your terminal and the aluminum frame to ensure you have a good ground.

When you ground one load, you may find a second load starts to work because they are using a common ground point.

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that

 

[kosier]

On both our 77s, the body is grounded to the frame at the right front body
mount. The frame is then grounded to the engine at the right rear engine
mount. And, of course, the engine is grounded directly to the battery.

Gary Kosier
77PB w/500Cad
Newark, Ohio

--------------------------------------------------
From: "Ken Burton"
Sent: Thursday, September 27, 2018 12:00 AM
To:
Subject: Re: [GMCnet] GMC ground points

> I had the same problem twice on two different coaches. I never found
> exactly where those two grounds were attached. One was a 1978 and I do
> not
> remember the year on the other one. I will tell you that the aluminum
> body is the master ground for the house system. So I gave up and ran
> another
> ground wire to the aluminum body. Problem solved.
> --
> 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

 

[Ken B]

Listen to Bruce's suggestions. He has it right.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[slc]

I can only comment on my own experience.
I have a 74 Glacier 260. I am the 4th owner after 3 PO's did their "upgrades". The last PO revamped the interior to maker her SELLABLE, not to use
her.
He had torn some of the interior out, there is no way of knowing how much damage he actually did to the coach but I am finding it one by one.

I had a problem with the interior lighting, and some other DC items, going out intermittantly. It took a long time to find what the cause was. I
ran for a long time with jumpers on the Negative to frame till I found it.

My GMC has the sink, with the furnace under it, on the driver side of the coach. The electrical cabinet is behind this cabinet, going toward the
rear.
I found the Negative lug connected to the coach frame behind the drawer cabinet, next to the sink, with a bolt that was only finger tight. Tightening
this bolt to reconnect the ground tightly cured the problem. I recall it was quiet the adventure to get back there to get this connection tight
again.

--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO -
UBUNTU VOYAGER - Berzin Auto Center