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[GMCnet] alternator [message #160996] Mon, 20 February 2012 11:27 Go to next message
Terry Skinner is currently offline  Terry Skinner   United States
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Registered: January 2004
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Senior Member
Want to know more about that alternator under the hatch?? Here you
go!! Also some stuff about how to bend a roll bar. Not much use unless
you are going to the salt flats.<G>


http://www.pirate4x4.com/tech/billavista/Wiring/Part2/
--
Terry Skinner
253-686-2624
Roy. Washington
'76 GMC
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Re: [GMCnet] alternator [message #161130 is a reply to message #160996] Tue, 21 February 2012 22:16 Go to previous messageGo to next message
midlf is currently offline  midlf   United States
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Registered: July 2007
Location: SE Wisc. (Palmyra)
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Terry Skinner wrote on Mon, 20 February 2012 11:27

Want to know more about that alternator under the hatch?? Here you
go!! Also some stuff about how to bend a roll bar. Not much use unless
you are going to the salt flats.<G>


http://www.pirate4x4.com/tech/billavista/Wiring/Part2/
--
Terry Skinner



I like the part where he explains how the GMC MH is solar powered.


Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
Re: [GMCnet] alternator [message #161155 is a reply to message #160996] Wed, 22 February 2012 09:01 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Location: S.E. Michigan
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Terry Skinner wrote on Mon, 20 February 2012 12:27

Want to know more about that alternator under the hatch?? Here you go!! Also some stuff about how to bend a roll bar. Not much use unless you are going to the salt flats.<G>

http://www.pirate4x4.com/tech/billavista/Wiring/Part2/
--
Terry Skinner

That is a really good article, but to those truly interested there are two errors that might be recognized.
All the old (1 and 2 wire) Delco alternators were "hot field". They used the ground leg to control the field power. That is why the "Jam a screwdriver here" test works. (See X7525, 6Y22, Fig 25)
The other is the stator output is hardly sinusoidal. His pictures are nice, but if compared to the real output, one might think that there was an issue. There is not. The taper of the field "claws" is designed to give a smoother DC output when rectified.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] alternator [message #161248 is a reply to message #161155] Thu, 23 February 2012 16:25 Go to previous messageGo to next message
Greg and April is currently offline  Greg and April   United States
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Is a "hot field' a good thing or a bad thing?
.

Greg H.

I don't just march to the beat of my own drum - I have an entire brass band
to keep me company.

.
----- Original Message -----
From: "Matt Colie" <matt7323tze@gmail.com>
To: <gmclist@temp.gmcnet.org>
Sent: Wednesday, February 22, 2012 8:01
Subject: Re: [GMCnet] alternator




That is a really good article, but to those truly interested there are two
errors that might be recognized.
All the old (1 and 2 wire) Delco alternators were "hot field". They used
the ground leg to control the field power. That is why the "Jam a
screwdriver here" test works. (See X7525, 6Y22, Fig 25)
The other is the stator output is hardly sinusoidal. His pictures are nice,
but if compared to the real output, one might think that there was an issue.
There is not. The taper of the field "claws" is designed to give a smoother
DC output when rectified.

Matt

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Re: [GMCnet] alternator [message #161255 is a reply to message #161248] Thu, 23 February 2012 17:36 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Registered: March 2007
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Greg and April wrote on Thu, 23 February 2012 17:25

Is a "hot field' a good thing or a bad thing?

Greg H.


Good Question Greg,
As near as I can tell, the only difference it makes is how you test the alternator and regulator.

I always liked being able to put a meter on the battery and jam the screwdriver in the D hole and see if the meter moves up. It is a completely Un-nervous test.

On the other hand, the others- like Mopar (iirc), you had to use a jumper from the output post to one of the terminals. (Oh, if you hit the frame of the alternator, your test lead would instantly heat to incandescence.)

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] Alternator [message #345243 is a reply to message #160996] Sat, 13 July 2019 17:29 Go to previous messageGo to next message
Ek_Lektro is currently offline  Ek_Lektro   United States
Messages: 167
Registered: March 2011
Karma: 2
Senior Member

> I just heard from a second friend their new alternators lasted approx.
> 10 days each. They went thru 3 or 4 before finding one that is now
> running. Seems to be common with the alternators being made today…

Between 2 coaches, i’d gone through about 3 or 4 Duralast alternators in the past 3 years.
The lifetime warranty at Autozone had me stuck in a painful loop.
(And this estimate is NOT including 2 other Duralasts that'd probably failed because
a neighborhood mechanic hooked the leads up backwards, and it was putting out 16v….
until thanks to a Jim Bounds consultation call, i traced what was going on.
Yes, my coach doesn’t have the stock double connector anymore, so you gotta be careful)

So finally i decided to try an AC Delco from O’Reillys, branded as Ultima.
I’ve only put about 500 miles on it so far, and It hasn’t blown out on me yet,
however i’m pretty disappointed that its only putting out 13.2 volts!
The “GEN” light does not come on, and the belt is tight, so wondering what’s the issue here?
(BTW: This is on the Eleganza, not the Birchhaven which is having the ignition / battery / starter issue)

Also, last time i had the Eleganza out in the evening, with headlights on, and needed to raise airbags,
the alternator seemed to temporarily stop working. my analog voltage gauge dipped down to
12 volts, and i could hear the compressor motor struggling.

So now that the Birchhaven starter situation might be handled (more on that in a later post)
i’m gonna dig into the Eleganza alternator issue and see what i can see.
Wondering if one of my 10 year old Viair pumps is getting tired, and taxing the system.
(It makes a lower growling noise compared to the other one, but seems to raise just as fast)
Connections are tight. Grounds are good. Hmmmmm….

Anyway, yes, alternator quality (at Autozone at least) was pretty atrocious. Right out of the box, many of the blades are bent
and hitting against the housing. I’ll see what i can do about this AC Delco and report any new findings

Cheers!
Greg / SolarSonic / LosAngeles
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Re: [GMCnet] Alternator [message #345245 is a reply to message #345243] Sat, 13 July 2019 18:35 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Registered: March 2007
Location: S.E. Michigan
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The problem with "Rebuilt" any electric thing is that the devices are often reworked by local shops and put into a "Fill in the name" box that is stamps with a part number (about 80% accurate). I know for a fact that the local NAPA warehouse gets such things from three different shops. I was in the one I like most recently and they were returning the unused boxes with NAPA labels. They had lost the bid.

For this reason, if you can find a local shop to patronize. You have a better chance at getting the job done right. They know that you know who they are and where to come back to if there is a problem.

I have a fun story about this, but it has been a long day for me....

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] Alternator [message #345247 is a reply to message #345243] Sat, 13 July 2019 18:44 Go to previous messageGo to next message
Ek_Lektro is currently offline  Ek_Lektro   United States
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Registered: March 2011
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Senior Member
13.2v max is flat defective. replace it. you need 14.2v hot, 14.3-4
cold or you will slowly destroy your batteries by not fully charging.

On 2019-07-13 18:29, Ek Lektro via Gmclist wrote:

>> I just heard from a second friend their new alternators lasted approx.
>> 10 days each. They went thru 3 or 4 before finding one that is now
>> running. Seems to be common with the alternators being made today...
>
> Between 2 coaches, i'd gone through about 3 or 4 Duralast alternators in the past 3 years.
> The lifetime warranty at Autozone had me stuck in a painful loop.
> (And this estimate is NOT including 2 other Duralasts that'd probably failed because
> a neighborhood mechanic hooked the leads up backwards, and it was putting out 16v....
> until thanks to a Jim Bounds consultation call, i traced what was going on.
> Yes, my coach doesn't have the stock double connector anymore, so you gotta be careful)
>
> So finally i decided to try an AC Delco from O'Reillys, branded as Ultima.
> I've only put about 500 miles on it so far, and It hasn't blown out on me yet,
> however i'm pretty disappointed that its only putting out 13.2 volts!
> The "GEN" light does not come on, and the belt is tight, so wondering what's the issue here?
> (BTW: This is on the Eleganza, not the Birchhaven which is having the ignition / battery / starter issue)
>
> Also, last time i had the Eleganza out in the evening, with headlights on, and needed to raise airbags,
> the alternator seemed to temporarily stop working. my analog voltage gauge dipped down to
> 12 volts, and i could hear the compressor motor struggling.
>
> So now that the Birchhaven starter situation might be handled (more on that in a later post)
> i'm gonna dig into the Eleganza alternator issue and see what i can see.
> Wondering if one of my 10 year old Viair pumps is getting tired, and taxing the system.
> (It makes a lower growling noise compared to the other one, but seems to raise just as fast)
> Connections are tight. Grounds are good. Hmmmmm....
>
> Anyway, yes, alternator quality (at Autozone at least) was pretty atrocious. Right out of the box, many of the blades are bent
> and hitting against the housing. I'll see what i can do about this AC Delco and report any new findings
>
> Cheers!
> Greg / SolarSonic / LosAngeles
> _______________________________________________
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> Unsubscribe or Change List Options:
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Re: [GMCnet] alternator [message #345249 is a reply to message #160996] Sat, 13 July 2019 19:32 Go to previous message
JohnL455 is currently offline  JohnL455   United States
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I redid my own working 80A by replacing bearings and brushes. If the diodes and regulator are
good I leave them. I Deoxit D5 cleaned all internal connections. Then drove Chicago Seatle Chicago to "road test". No issues.


John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] alternator [message #345252 is a reply to message #345249] Sun, 14 July 2019 05:45 Go to previous message
Bruce Hart is currently offline  Bruce Hart   United States
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Senior Member
John, how do you test the voltage regulator?

On Sat, Jul 13, 2019 at 7:02 PM John R. Lebetski via Gmclist <
gmclist@list.gmcnet.org> wrote:

> I redid my own working 80A by replacing bearings and brushes. If the
> diodes and regulator are
> good I leave them. I Deoxit D5 cleaned all internal connections. Then
> drove Chicago Seatle Chicago to "road test". No issues.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
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--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
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Bruce Hart 1976 Palm Beach 1977 28' Kingsley La Grange, Wyoming
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