electrical charging problem 77 eleganza

LQQKatJon

Well-known member
Oct 22, 2010
3,233
558
113
St. Cloud, Mn
lqqkatjon.blogspot.com
Ok, I helped a friend get into GMC's, and I understood from the start, that I may have inherited a second GMC to keep running, but the good thing
is I do not have to pay any of my own money on it.

My problem is trying to balance time between work, family, my own projects, ect.. ect... So I was hoping to get some advice to maybe give me a
starting point when I go over and try to figure out the elecrical problem his GMC has now developed.

We had the battery isolator bad on our trip back home, So when it got back, we replaced the battery cables, isolator, boost solenoid, had the
alternator rebuilt. (rebuilder said it looked good-but changed the brushes). I also had him install a PD converter and sent the buzz box over to my
ham radio friend.

for the most part the 77 eleganza 2 looks original, but someone had cut and rewired all the wires to the fuse panel. They looked to do a good job
for the most part, heat shrinking connections, and keeping all the same wire colors. so basically the harness is all the same, but the last 6-8"
of wire going into the fuse block is replaced. It does look like he kept it all original though.

I had everything working as I thought it should when I sent him home with it. All 3 posts of the isolator were properly putting out 14+volts, and
it seemed good.

Now it quit charging. and further diagnosis, we seem to not have dash lights now, and the fuse seemes burnt for the dash lights.(the one tiny
fuse...what is with that pain!). But now I do not even have 12V power on either side of that fuse.

What also is going on, is with engine running (I am guessing with ignition on... not necessary engine running I forgot to check and am now just
gathering my thoughts). is there is the coach and engine batteries are connected(with house battery disconnected, we are getting power to the house
side. when I had it running). Boost solenoid is new and working correctly.

I am also getting 10v off the center post to alternator.

I am guessing I am having a "sense" wire problem to the alternator. Plus something is shorted or wired wrong in the dash connecting the ignition
feed to something on the house side. thinking back, this could of been a problem all along, but i do not think so, because originally when the
isolator was failed on the drive home, we were not getting battery power from the coach battery over to the engine battery without engaging the boost
solenoid.

So any help where to start looking to where the ignition wire might be crossed or shorting over to the coach side. Also is there a easy way to wire
the voltage sensing wire over to the alternator as a temp fix? I am trying to talk him into camping this weekend with me, so I have all weekend to
work on it at the campground. but need to get charging situation fixed to run the lights because it gets dark so early. otherwise I do not have
much time before then.

FYI- there is no APC cable. he ordered one over the weekend and hopefully may have it this week to install.

thanks for all help.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
As to the dash lights -- the fuse gets its power through the headlight switch. If you rotate the headlight switch it will dim the dash lights and even turn them off. If you aren't getting any voltage to that fuse you may have the headlight switch turned off.
You could also possibly have a bad headlight switch. If you need instructions for removing the headlight switch let us know.

If you are only getting 10 volts from the alternator it sounds like you have a bad alternator or with its built in voltage regulator.
Probably not a sence wire as that usually causes over voltage other than low voltage if the alternator is working properly.

Emery Stora
77 Kingsley
Frederick, CO

>
> Ok, I helped a friend get into GMC's, and I understood from the start, that I may have inherited a second GMC to keep running, but the good thing
> is I do not have to pay any of my own money on it.
>
> My problem is trying to balance time between work, family, my own projects, ect.. ect... So I was hoping to get some advice to maybe give me a
> starting point when I go over and try to figure out the elecrical problem his GMC has now developed.
>
>
> We had the battery isolator bad on our trip back home, So when it got back, we replaced the battery cables, isolator, boost solenoid, had the
> alternator rebuilt. (rebuilder said it looked good-but changed the brushes). I also had him install a PD converter and sent the buzz box over to my
> ham radio friend.
>
> for the most part the 77 eleganza 2 looks original, but someone had cut and rewired all the wires to the fuse panel. They looked to do a good job
> for the most part, heat shrinking connections, and keeping all the same wire colors. so basically the harness is all the same, but the last 6-8"
> of wire going into the fuse block is replaced. It does look like he kept it all original though.
>
>
> I had everything working as I thought it should when I sent him home with it. All 3 posts of the isolator were properly putting out 14+volts, and
> it seemed good.
>
> Now it quit charging. and further diagnosis, we seem to not have dash lights now, and the fuse seemes burnt for the dash lights.(the one tiny
> fuse...what is with that pain!). But now I do not even have 12V power on either side of that fuse.
>
> What also is going on, is with engine running (I am guessing with ignition on... not necessary engine running I forgot to check and am now just
> gathering my thoughts). is there is the coach and engine batteries are connected(with house battery disconnected, we are getting power to the house
> side. when I had it running). Boost solenoid is new and working correctly.
>
> I am also getting 10v off the center post to alternator.
>
>
> I am guessing I am having a "sense" wire problem to the alternator. Plus something is shorted or wired wrong in the dash connecting the ignition
> feed to something on the house side. thinking back, this could of been a problem all along, but i do not think so, because originally when the
> isolator was failed on the drive home, we were not getting battery power from the coach battery over to the engine battery without engaging the boost
> solenoid.
>
>
>
> So any help where to start looking to where the ignition wire might be crossed or shorting over to the coach side. Also is there a easy way to wire
> the voltage sensing wire over to the alternator as a temp fix? I am trying to talk him into camping this weekend with me, so I have all weekend to
> work on it at the campground. but need to get charging situation fixed to run the lights because it gets dark so early. otherwise I do not have
> much time before then.
>
> FYI- there is no APC cable. he ordered one over the weekend and hopefully may have it this week to install.
>
>
> thanks for all help.
> --
> 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
 
thanks.

been messing with headlight switch, On/Off, rotating it varying degrees Headlights work.

headlight switches i think are cheap and readily available. I am aware how those things come out.

You are possibly right about the alternator, Not that much work to yank it out again and have it tested.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> thanks.
>
> been messing with headlight switch, On/Off, rotating it varying degrees Headlights work.
>
> headlight switches i think are cheap and readily available. I am aware how those things come out.
>
> You are possibly right about the alternator, Not that much work to yank it out again and have it tested.

Jon,

It is possible for the instrument lights to short to ground. When this happens, the fuse goes out at some strange place in the "bright to dim" range.


If you have to get the alternator tested, be very sure that what goes back in has the remote sense regulator. It is not that uncommon, but it is not
the most common installed.

You might try the light bulb across the fuse clips trick to diagnose that circuit.

Good luck

Matt
--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit