Alternator went Bad

E

emerystora

New member
Apr 6, 1999
14,608
1
1
We were returning home from Phoenix and were driving along on I-40 just west of the NM border and our voltmeter suddenly showed 18 volts.
Apparently the voltage regulator went bad in the alternator.

Fortunately I carry a spare so I pulled off the highway into a closed truck weigh station.
I removed the alternator and was about to try pushing the new one up from the bottom when Hal St Clair walked up to my motorhome.
He offered to help and so I pushed it up from the bottom and he pulled it from the top. Hal got the mounting pin mounted into it and I felt I could take care of it from there.

The new alternator worked fine.

Thank you, Hal for your assistance. You seem to be helping a lot of GMCers lately. Bob Dunahugh especially with his water pump problem.

Emery Stora
77 Kingsley
Frederick, CO
 
The GMC community is a very helpful group.
At our age, when there is another hand to help makes for efforts to be easy
to accomplish.

> We were returning home from Phoenix and were driving along on I-40 just
> west of the NM border and our voltmeter suddenly showed 18 volts.
> Apparently the voltage regulator went bad in the alternator.
>
> Fortunately I carry a spare so I pulled off the highway into a closed
> truck weigh station.
> I removed the alternator and was about to try pushing the new one up from
> the bottom when Hal St Clair walked up to my motorhome.
> He offered to help and so I pushed it up from the bottom and he pulled it
> from the top. Hal got the mounting pin mounted into it and I felt I could
> take care of it from there.
>
> The new alternator worked fine.
>
> Thank you, Hal for your assistance. You seem to be helping a lot of
> GMCers lately. Bob Dunahugh especially with his water pump problem.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
I changed the alternator on my 78. 403 from the top. Is yours a 455?
--
Cary, NC

1978 Center Kitchen Royale.
 
Emery,

I had the same thing happen going to I believe it was Dothan. The only indication that I had was a way over voltage reading. I kept the voltage down
to normal ranges by running with the headlights, heater fan, and some running lights on.

After arriving I pulled the alternator and Colonel Ken me to Autozone for a free exchange. Upon installing the new one it worked for a while and the
new one went over voltage too. Upon further diagnosis I discovered the APC connector what plugged into the alternator had lost it's tension over many
years of driving. A simple tightening (squeezing it with pliers) fixed the problem. I mention this just in case yours was the same problem and
re-plugging the new alternator cleared the problem. Should the problem reappear, pull the APC plugs and tighten them before declaring the new
alternator bad.

I wish I had done that first. It would have saved me a lot of work and Colonel Ken from running me to AutoZone twice. Ken is always bailing me out.
Last year it was a bad fuel pump at BS. He and Manny towed me in to the rally. He and you have done that many times. Remember the radiator at
Harrington?
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Yes, it’s a 455. Everything can be disconnected from the top but there just isn’t room to lift it out past the bracket.

Emery Stora
77 Kingsley
Frederick, CO

>
> I changed the alternator on my 78. 403 from the top. Is yours a 455?
> --
> Cary, NC
>
> 1978 Center Kitchen Royale.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
When I did a bench refresh on my 80A I used the bearings and brushes in the kit but opted to leave the old working GM reg and diodes in place. I
trusted them more than the new offshore replacements. Plus they are well "burned in" and less likely to fail during that period. So far so good.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
I pulled the one out of my 23' from th top with some gyrations. It's doable.
That being said, a high volrtage is almost ale=ways a loss of reference voltage due to a poor connection of the plug on the side of the alternator.
These alternators run fairly hot, which eventualkly kills the 'spring' in the contacts. Bend them and go another 20 years or so.

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
> I pulled the one out of my 23' from th top with some gyrations. It's doable.
> That being said, a high volrtage is almost ale=ways a loss of reference voltage due to a poor connection of the plug on the side of the
> alternator. These alternators run fairly hot, which eventualkly kills the 'spring' in the contacts. Bend them and go another 20 years or so.
>
> --johnny

That is the exact problem that I had. Unfortunately I did not do thorough diagnosis before replacing mine and replaced the alternator needlessly.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Me either, the first time, Ken :) Maybeso this will help someone else from making the same mistake.

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
It was no mistake. The auto parts store tested it and confirmed that the voltage regulator went bad and gave me a replacement.

It may be possible for some to remove it from the top of a 455 but in my case I would have had to remove duct work going from my remote filter to the carb filter so it was easier for me to move it down

Emery Stora
77 Kingsley
Frederick, CO

>
> Me either, the first time, Ken :) Maybeso this will help someone else from making the same mistake.
>
> --johnny
> --
> 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> "I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
No Billy, Emery had the right NM Hal. The other Hal (from Rio Rancho) also helped me get out of Tucson after the rally. SOB jack wouldn't retract and
I managed to dislodge the base plate. Bright and early Thursday morning Hal was at the door with a hand full of tools. A few minutes later he had the
base plate back in place and the jack retracted far enough to travel. Thanks again Hal!

Hal Kading 78 Buskirk Stretch (and SOB) Las Cruces NM
 
I also had a 6 month old NAPA alternator that was putting out 18 volts.
Had it tested at NAPA and it tripped out the test equipment twice.
Got a new alternator on warranty.
My plug from the APC would could go on either way. I replaced with new
connector cover so it fits only in the correct position.

https://www.napaonline.com/en/p/ECHVRC148

> No Billy, Emery had the right NM Hal. The other Hal (from Rio Rancho) also
> helped me get out of Tucson after the rally. SOB jack wouldn't retract and
> I managed to dislodge the base plate. Bright and early Thursday morning
> Hal was at the door with a hand full of tools. A few minutes later he had
> the
> base plate back in place and the jack retracted far enough to travel.
> Thanks again Hal!
>
> Hal Kading 78 Buskirk Stretch (and SOB) Las Cruces NM
>
> _______________________________________________
> 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
 
Was not an Apc 😕

> I also had a 6 month old NAPA alternator that was putting out 18 volts.
> Had it tested at NAPA and it tripped out the test equipment twice.
> Got a new alternator on warranty.
> My plug from the APC would could go on either way. I replaced with new
> connector cover so it fits only in the correct position.
>
> https://www.napaonline.com/en/p/ECHVRC148
>

>
> > No Billy, Emery had the right NM Hal. The other Hal (from Rio Rancho)
> also
> > helped me get out of Tucson after the rally. SOB jack wouldn't retract
> and
> > I managed to dislodge the base plate. Bright and early Thursday morning
> > Hal was at the door with a hand full of tools. A few minutes later he had
> > the
> > base plate back in place and the jack retracted far enough to travel.
> > Thanks again Hal!
> >
> > Hal Kading 78 Buskirk Stretch (and SOB) Las Cruces NM
> >
> > _______________________________________________
> > 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
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://bdub.net/gmcmotorhome.info/
Alternator Protection Cable
http://bdub.net/gmcmotorhome.info/APC.html
 
> It was no mistake. The auto parts store tested it and confirmed that the voltage regulator went bad and gave me a replacement.
>
> It may be possible for some to remove it from the top of a 455 but in my case I would have had to remove duct work going from my remote filter to
> the carb filter so it was easier for me to move it down
>
> Emery Stora
> 77 Kingsley
> Frederick, CO

Sorry Emery,

but most of those people testing alternator in stores do not know what they are doing when testing. The standard cable they use does not have any
voltage feed back on the voltage sense line. There is a special adapter that they need to use on the end of that cable that wires the +12 volt out
the the voltage sense line. I watched two different AutoZones do that on mine. I also watched one NAPA store do the same thing. At AZ I wanted a
new one at the time so I did not say anything when it failed at 2 different stores. After I later discovered the real problem, I was tempted to go
get my original back. I did not because they gave me a hassle about changing my double pulley over. I figured it was not worth the effort. The
first one said there was absolutely no problem changing the pulley, but they did not have one in stock. They sent us to a second store who had it.
That store refused to change the pulley and we did not have any tools with us.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
> No Billy, Emery had the right NM Hal. The other Hal (from Rio Rancho) also helped me get out of Tucson after the rally. SOB jack wouldn't retract
> and I managed to dislodge the base plate. Bright and early Thursday morning Hal was at the door with a hand full of tools. A few minutes later he
> had the base plate back in place and the jack retracted far enough to travel. Thanks again Hal!
>
> Hal Kading 78 Buskirk Stretch (and SOB) Las Cruces NM

I'm thinking of starting a GoFundMe page to solicit money to clone Hal St. Clair. Anybody know how much that costs? He's a huge asset to the
community and whatever it costs it would be worth it!

Richard

--
'77 Birchaven TZE...777
Yes, I am lucky!
 
Gee guys, I'm really flattered but there are many, many here more deserving. I was just blessed to be at the right place at the right time.
As for the 'cloning' Richard, I think my wonderful wife might have an issue with that.Blush. She's been trying to train me for 46+ years with at best
mixed results. Adding more to her work load might not go over too well.
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1975 Eleganza II, 101230,

1974 Eagle Bus 45',w/slideout,

Rio Rancho, NM
 
Hal,
If there were two of you, one could go to the movies and take long walks with Blanca while the other one was wrenching.
Just saying... :)

Richard
--
'77 Birchaven TZE...777
 
My "Mens mall" special went out after 7 years, so managed to get another from pepboys on special for a hundred bux and a lifetime guarantee. do you
guys still run a stock alt or did anyone upgrade to the 140 amp out of a 95 caddy? I run the latter to make sure I got extra juice and since I used
electric fans to coll the radiator...
--
73 Canyon Lands, (a.k.a. The Yellow Submarine) West Los Angeles CA
 
In 1978 (and maybe previous years) GMC offered a 145 amp alternator. The only one I ever saw was on an transmode people mover. That one was a one
wire alternator without remote sensing. So it would only work on a single battery non-isolator system. If one was to use one of these they could
also buy an aftermarket combiner to get multi-battery systems to work.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
I pretty much took everything out of a 95 Eldo. Then wired the sensing wire to a relay feed the sensor that would click on with ignition power to the
field would energize. Works like a charm, but I do recommend the double belt pulley. you have to reclock the alt but thats easy and takes like 5
minutes. then run a 4 gauge wire off the back of the alt to the isolator and boom you're good to go.
--
73 Canyon Lands, (a.k.a. The Yellow Submarine) West Los Angeles CA
 
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