Electrical problem. Need help

[LQQKatJon]

Helping my friend. 1977 eleganza ii. All systems seemed to work well, then it just died.

But then came alive.

Batteries are good.

Here is info:
Head lights don't work. Looks like another new switch. There is something differently wrong. If the dash lights don't come on, there is no power to
start it. If the dash lights work, than I can start it. But I made it up here. It's cold and windy. Jeff says

Headlight switch is new. Any idea how power gets to starter/ect??? That would be related??

Checking basics,
But all should be ok. Pushing boost did not work. Should have good battery connections.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[Ken H.]

Jon,

If you don't have the chassis wiring diagram, you should download it from
bdub.net.

Looking at that diagram, you'll see that there are numerous possible
locations for the sort of intermittent failure you're experiencing, but the
most likely is the Fusible Link, through which all chassis power except the
primary starter current must pass. It's easy to find that -- in the left
margin of the diagram there's a label at the level of the actual diagram.

Since that little 16 gauge wire carries a LOT of current all the time the
coach is in operation, it, and its connectors do deteriorate over time and
can be come intermittent. You should be able to buy replacement wire at
'most any auto parts store. DON'T just replace it with ordinary wire -- it
may run too hot for ordinary insulation.

Ken H.

> Helping my friend. 1977 eleganza ii. All systems seemed to work well,
> then it just died.
>
> But then came alive.
>
> Batteries are good.
>
> Here is info:
> Head lights don't work. Looks like another new switch. There is something
> differently wrong. If the dash lights don't come on, there is no power to
> start it. If the dash lights work, than I can start it. But I made it up
> here. It's cold and windy. Jeff says
>
> Headlight switch is new. Any idea how power gets to starter/ect??? That
> would be related??
>
> Checking basics,
> But all should be ok. Pushing boost did not work. Should have good
> battery connections.
> --

 

[terry1]

Check the main connections at the battery post, starter, and ground wire on the engine block. Starter power comes right from the battery, but the
signal wire to trigger it may be fed from the connection at the starter, like most early GM cars. In forty years some owners may have made
modifications to that setup, so YMMV.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[LQQKatJon]

Thanks Ken.

I was looking over the diagrams on my phone and I came to that same fusable link as a probable culprit. You are confirming that educated guess.

The coach is a friend of mine I helped buy the coach. I am on my family camp trip and he headed north to thunder bay canada this weekend. So trying
to help fix over phone. Electrical stuff is one thing that he struggles with.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[sean kidd]

+1 for the main battery connections, they may look tight and be tight, but a layer of corrosion will insulate posts...remove, clean, reinstall, spray
with battery terminal protector...also check chassis side of ground...
--
Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.

Colonial Travelers

 

[wally anderson]

> Helping my friend. 1977 eleganza ii. All systems seemed to work well, then it just died.
>
> But then came alive.
>
> Batteries are good.
>
> Here is info:
> Head lights don't work. Looks like another new switch. There is something differently wrong. If the dash lights don't come on, there is no power
> to start it. If the dash lights work, than I can start it. But I made it up here. It's cold and windy. Jeff says
>
> Headlight switch is new. Any idea how power gets to starter/ect??? That would be related??
>
> Checking basics,
> But all should be ok. Pushing boost did not work. Should have good battery connections.

Here is picture of the fusable link, not my pic.
http://www.gmcmhphotos.com/photos/misc-gmc-photos/p36632-fusable-link.html
http://www.gmcmhphotos.com/photos/misc-gmc-photos/p36632-fusable-link.html
--
Wally Anderson
Omaha NE
75 Glenbrook
Megasquirt III injection
Bob Stone hydroBOOOOST
Manny reaction arm system
Branscombe Kelsey Hayes park brake
http://wallyandsue.blogspot.com/

 

[Ken B]

Clean the battery cables thoroughly. Sometimes a round battery cable brush is not good enough. I have had to take a rat tail file to the battery
cables to get them clean enough to really make good high current contact.

The fusible link that Colonel Ken mentioned is right in front of you when you open the passenger side hood. Move it around and flex it a bit to see
if it is burned. A better way is to check all connections including the fusible link with a volt meter under load.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[LQQKatJon]

Last communication they are not thinking it is that fusable link. Everything seems working, except headlights now. I am told high beams work, so
maybe the floor switch.

But I still wonder about the fusable link and such, and i will be checking everything once it is back in my driveway next week. Something was loose
or changed causing no power. Headlights could of died too, even though they are new this spring.

Asked them to check grounds and battery cables, but I did replace all battery cables, and such last fall. They should be in good shape.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[Jim Hupy]

Check the wire harness connector on or near the dimmer switch, and the
dimmer switch itself. I have encountered similar issues as you describe,
and found problems there.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> Last communication they are not thinking it is that fusable link.
> Everything seems working, except headlights now. I am told high beams
> work, so
> maybe the floor switch.
>
> But I still wonder about the fusable link and such, and i will be
> checking everything once it is back in my driveway next week. Something
> was loose
> or changed causing no power. Headlights could of died too, even though
> they are new this spring.
>
> Asked them to check grounds and battery cables, but I did replace all
> battery cables, and such last fall. They should be in good shape.
>
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[terry1]

Check the bulkhead/firewall connection...should have mentioned that in my earlier post :?
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[terry1]

That is, the one behind the fusebox.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[david shafer]

Fusible link is designed to be a one time failure protection device. I've never seen intermittent... though I have not seen that many. Often they blow
but it is not obvious to see. The insulation holds together but is very flexible where the melting occurred. If you stretch the fusible link you'll
see the insulation at the fault point get thin. very much like a rubber band.
--
1977 26 foot 403

 

[LQQKatJon]

Quick update:

Coach made it up north of Thunder Bay, and back home to my driveway in central MN, only repeating the dead ignition 3 times. They also realized that
they had no high beam headlights.

Diagnosis now was the wiring mess the PO did feeding off the fuse block, and just had bad connections. The high beams and the ignition problem were
two separate issues. Looks like the high beams and the low beams feed 12v off of different spots of the fuse panel, and one was not making contact.

Anyway- I replaced the perfectly good fusable link with a new one(auto parts store sells that with correct ring terminals), and I traced out the
problems.

the connectors and wiring harness off the fuse panel needs to be replaced, and i just happen to know where one is sitting 80 miles away, so I should
have that in the next couple weeks. In the mean time, I know where to look for the problem, and I rigged it a little better, so it should work for a
while.

Thanks for all the help.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/