Main Dash Ground Location 77 Eleganza II

[jared1]

When I got Recherche back, I noticed that there were some electrical issues.

None of the front clearance lights are functioning, as well as the switched interior driving compartment lights (next to your head where the little
speaker is).

Going through the wiring diagrams, both of these get their grounds from the Main Dash Ground.

I pulled the front panel off the gauges so I could look through the stereo hole, and any other available holes, but can't see where it is.

Who can tell me where the Main Dash Ground is located?

Thanks, Jared
--
Jared & Tina Lazaron + 14yr old Daughter.....

77 Eleganza II "Recherché".....

73 Canyon Lands 230 "Elephant"

 

[Ken B]

The main dash ground is the aluminum plate that all of the dash instruments and radio are mounted in.

It gets its path to ground through one wire that goes through the firewall and terminates on the aluminum plate under the passenger side hood that the
isolator and other things are mounted on it. There is a second wire mounted on the under hood aluminum plate that goes direct to the negative battery
post.

It is very common for either of those wires to develop oxide resistance connections on the aluminum plates or for them to loosen up. Clean all three
of them up and reinstall with tooth washers between the three terminals and the plates.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[jared1]

> The main dash ground is the aluminum plate that all of the dash instruments and radio are mounted in.
>
> It gets its path to ground through one wire that goes through the firewall and terminates on the aluminum plate under the passenger side hood that
> the isolator and other things are mounted on it. There is a second wire mounted on the under hood aluminum plate that goes direct to the negative
> battery post.
>
> It is very common for either of those wires to develop oxide resistance connections on the aluminum plates or for them to loosen up. Clean all
> three of them up and reinstall with tooth washers between the three terminals and the plates.

Thanks Ken, I will give it a shot. Do you know by chance, the routing of the harness for the front clearance lights?

Jared

--
Jared & Tina Lazaron + 14yr old Daughter.....

77 Eleganza II "Recherché".....

73 Canyon Lands 230 "Elephant"

 

[Bruce Hart]

The wire harness passes through the area under the drivers toll window

On Sat, Oct 17, 2020 at 9:58 PM Jared via Gmclist
wrote:

> > The main dash ground is the aluminum plate that all of the dash
> instruments and radio are mounted in.
> >
> > It gets its path to ground through one wire that goes through the
> firewall and terminates on the aluminum plate under the passenger side hood
> that
> > the isolator and other things are mounted on it. There is a second wire
> mounted on the under hood aluminum plate that goes direct to the negative
> > battery post.
> >
> > It is very common for either of those wires to develop oxide resistance
> connections on the aluminum plates or for them to loosen up. Clean all
> > three of them up and reinstall with tooth washers between the three
> terminals and the plates.
>
> Thanks Ken, I will give it a shot. Do you know by chance, the routing of
> the harness for the front clearance lights?
>
> Jared
>
> --
> Jared & Tina Lazaron + 14yr old Daughter.....
>
> 77 Eleganza II "Recherché".....
>
> 73 Canyon Lands 230 "Elephant"
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class

 

[powwerjon]

Jarad,
Do you have the GMC Factory Manuals for your coach? They can be had at: http://www.bdub.net/manuals/index.html

If you go to manual X-7525B, Section 12, Page 12-19, Fig. 26 at the top left of the page if shows the front wiring routes.

You have a 77 Eleganza II and manual X-7725, Section 12, Page 12-5, Fig 10 indicates the ground for the dash area and the path of the connector for the front roof harness. Section 12 is quite descriptive of the electrical layout of the dash area of the 77s and later coaches.

The manuals are your best friend and you should not be without them and they are free. You can find original manuals sometimes and I think that you can still get reprints from Cinnabar. https://www.thegmcmotorhomepeople.com/publications/ I keep my manual in my home office and copy the pages and then use those to work in the shop, when done I take any notes that show what I have found and put them on a sticky note and attach the note to the page in the manual. You need to download both X-7525 & X-7725 manuals as they are a set. Ken B. is also a great storehouse of knowledge of these GMC’s.

Regards,

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

>
> The main dash ground is the aluminum plate that all of the dash instruments and radio are mounted in.
>
> It gets its path to ground through one wire that goes through the firewall and terminates on the aluminum plate under the passenger side hood that the
> isolator and other things are mounted on it. There is a second wire mounted on the under hood aluminum plate that goes direct to the negative battery
> post.
>
> It is very common for either of those wires to develop oxide resistance connections on the aluminum plates or for them to loosen up. Clean all three
> of them up and reinstall with tooth washers between the three terminals and the plates.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana

 

[jared1]

> Jarad,
> Do you have the GMC Factory Manuals for your coach? They can be had at: http://www.bdub.net/manuals/index.html
>
> If you go to manual X-7525B, Section 12, Page 12-19, Fig. 26 at the top left of the page if shows the front wiring routes.
>
> You have a 77 Eleganza II and manual X-7725, Section 12, Page 12-5, Fig 10 indicates the ground for the dash area and the path of the connector
> for the front roof harness. Section 12 is quite descriptive of the electrical layout of the dash area of the 77s and later coaches.
>
> The manuals are your best friend and you should not be without them and they are free. You can find original manuals sometimes and I think that
> you can still get reprints from Cinnabar. https://www.thegmcmotorhomepeople.com/publications/ I keep my manual in my home office and copy the
> pages and then use those to work in the shop, when done I take any notes that show what I have found and put them on a sticky note and attach the
> note to the page in the manual. You need to download both X-7525 & X-7725 manuals as they are a set. Ken B. is also a great storehouse of
> knowledge of these GMC’s.
>
> Regards,
>
> J.R. Wright
> GMC Great Laker MHC
> GMCGL Tech Editor
> GMC Eastern States Charter Member
> GMCMI
> 78 GMC Buskirk 29.5’ Stretch
> 75 GMC Avion (Under Reconstruction)
> Michigan

It's funny because I have a 7425 and the 7725 manuals/books, but no 7525.

I got it figured out, but I am even more confused than I was. I forgot to check the simple thing first and there were no bulbs in the sockets.... and
some of the sockets had no guts. The wires were there but clipped off. My first thought was WTF? All of the lights worked with brand new bulbs, brand
new lenses, and new gaskets when I sold the coach 6 years ago.... what happened between then and now is anyone's guess.

I'm looking for 3 replacement bases with sockets and wiring if anyone has any.
--
Jared & Tina Lazaron + 14yr old Daughter.....

77 Eleganza II "Recherché".....

73 Canyon Lands 230 "Elephant"