Home » Public Forums » GMCnet » more A/C questions (compressor clutch, fusable link)
| more A/C questions [message #132230] |
Mon, 27 June 2011 10:21  |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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I wish I had more time to work on my GMC. I hate to bother everybody, but the gmcnet really makes the time I do have to work on it so much more efficient.
I have a 75 palm beach.
Dash A/C is not working. Was not too bothered, because the ONAN did work. and so did the roof air. now that thing quit running.
Looks like my clutch for the A/C is not kicking in. I have jumpered the wires at the low charge cut off, and it is still not kicking on the clutch.
Can i just hit the clutch with 12Volts at the compressor to diagnose if it is the clutch itself, or some other electrial switching problem for the clutch?
this is a 7 to 10+ year sitting coach. so is there any knocking or cleaning of the clutch if it is having some problems? any shade tree mechanic way of getting it going without spending money? or before I have a sit down with the wife about finding extra money in the checkbook.
Other question is the relay just up to the right from the isolator. there is a red-white wire. that to me, looks to come down, hook to a fusable link. and then go to the fuse panel. That fusable link wire gets pretty dang hot with the fan blowing/A/C switched on. I did not measure the amps, but it shows 14.7 volts with engine running. the fusable link looks to be slightly less guage wire then the red-white. and it has a crappy butt splice connection.
before I replace that fusable link with a newer, better connected one... What should I be looking for with that wire, as not to have it burn up?
also I know I should buy duracool and put that in, but I have a bottle of r-12. any thoughts/process as to adding oil with the r-12?
I wish I had more detail, but my diagnose time is limited between work, wife, 2 kids.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: more A/C questions [message #132247 is a reply to message #132230] |
Mon, 27 June 2011 11:36  |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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| Jon wrote on Mon, 27 June 2011 10:21 |
I wish I had more time to work on my GMC. I hate to bother everybody, but the gmcnet really makes the time I do have to work on it so much more efficient.
I have a 75 palm beach.
Dash A/C is not working. Was not too bothered, because the ONAN did work. and so did the roof air. now that thing quit running.
Looks like my clutch for the A/C is not kicking in. I have jumpered the wires at the low charge cut off, and it is still not kicking on the clutch.
Can i just hit the clutch with 12Volts at the compressor to diagnose if it is the clutch itself, or some other electrial switching problem for the clutch?
this is a 7 to 10+ year sitting coach. so is there any knocking or cleaning of the clutch if it is having some problems? any shade tree mechanic way of getting it going without spending money? or before I have a sit down with the wife about finding extra money in the checkbook.
Other question is the relay just up to the right from the isolator. there is a red-white wire. that to me, looks to come down, hook to a fusable link. and then go to the fuse panel. That fusable link wire gets pretty dang hot with the fan blowing/A/C switched on. I did not measure the amps, but it shows 14.7 volts with engine running. the fusable link looks to be slightly less guage wire then the red-white. and it has a crappy butt splice connection.
before I replace that fusable link with a newer, better connected one... What should I be looking for with that wire, as not to have it burn up?
also I know I should buy duracool and put that in, but I have a bottle of r-12. any thoughts/process as to adding oil with the r-12?
I wish I had more detail, but my diagnose time is limited between work, wife, 2 kids.
|
Jon,
Can you safely put a meter on the connection to the compressor and chack that you have 12v at that point?
As for the roof air -- did it just stop? You might check the connections in the power panel -- known to become loose, low voltage/no air. Or is it running but not cooling?
If the ac system has not been opened there should be no real need to add oil.
Others need to input on the fusible link.
Dennis
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] more A/C questions [message #132254 is a reply to message #132247] |
Mon, 27 June 2011 11:50 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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If you have a DuoTherm roof unit, many of them have a timed start delay for
the compressor. It will take at least two minutes of running before the
compressor will start, usually with a considerable amount of noise and
vibration, until one or two things happen. Either the noise is so great that
temporary hearing loss is suffered, or the unit stabilizes and the noise is
lessened. There is a relay that controls the start functions of the
compressor, and it is mechanical in nature, and is subject to mud dauber
invasions as well as corrosion effects. A good shot of contact cleaner
followed by a blast of compressed air usually brings them back to life.
There is a work around to allow the whole thing to start at the same time as
well, if any one is interested.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Mon, Jun 27, 2011 at 9:36 AM, Dennis Sexton <dennisfsexton@aol.com>wrote:
>
>
> Jon wrote on Mon, 27 June 2011 10:21
> > I wish I had more time to work on my GMC. I hate to bother everybody,
> but the gmcnet really makes the time I do have to work on it so much more
> efficient.
> >
> > I have a 75 palm beach.
> >
> > Dash A/C is not working. Was not too bothered, because the ONAN did
> work. and so did the roof air. now that thing quit running.
> >
> > Looks like my clutch for the A/C is not kicking in. I have jumpered the
> wires at the low charge cut off, and it is still not kicking on the clutch.
> >
> > Can i just hit the clutch with 12Volts at the compressor to diagnose if
> it is the clutch itself, or some other electrial switching problem for the
> clutch?
> >
> > this is a 7 to 10+ year sitting coach. so is there any knocking or
> cleaning of the clutch if it is having some problems? any shade tree
> mechanic way of getting it going without spending money? or before I have a
> sit down with the wife about finding extra money in the checkbook.
> >
> > Other question is the relay just up to the right from the isolator.
> there is a red-white wire. that to me, looks to come down, hook to a
> fusable link. and then go to the fuse panel. That fusable link wire gets
> pretty dang hot with the fan blowing/A/C switched on. I did not measure the
> amps, but it shows 14.7 volts with engine running. the fusable link looks
> to be slightly less guage wire then the red-white. and it has a crappy butt
> splice connection.
> >
> > before I replace that fusable link with a newer, better connected one...
> What should I be looking for with that wire, as not to have it burn up?
> >
> > also I know I should buy duracool and put that in, but I have a bottle of
> r-12. any thoughts/process as to adding oil with the r-12?
> >
> > I wish I had more detail, but my diagnose time is limited between work,
> wife, 2 kids.
>
>
> Jon,
>
> Can you safely put a meter on the connection to the compressor and chack
> that you have 12v at that point?
>
> As for the roof air -- did it just stop? You might check the connections in
> the power panel -- known to become loose, low voltage/no air. Or is it
> running but not cooling?
>
> If the ac system has not been opened there should be no real need to add
> oil.
>
> Others need to input on the fusible link.
>
> Dennis
>
> --
> Dennis S
> 73 Painted Desert 230
> Germantown, TN
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: more A/C questions [message #132262 is a reply to message #132230] |
Mon, 27 June 2011 12:11 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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sorry for confusion... both roof air work fine. onan quit running so i cant use roof air when on the move. so trying to get dash air going.
onan could be easy fix... i have not looked at that at all.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: more A/C questions [message #132279 is a reply to message #132247] |
Mon, 27 June 2011 13:14 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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check for 12 volts at compressor? I should of thought of that. I try to do that tonight. I should be able to sneak outside to do that!
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: [GMCnet] more A/C questions [message #132281 is a reply to message #132247] |
Mon, 27 June 2011 13:12 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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I'd leave the fusible link, but hang it out in the wind, not bundled with the rest of the harness. Reasining - If you replace it with a fuse and fuseholder (available from auto sound shops), you lose the time delay feature of the link. touch the genset battery lead inadvertantly with a tool and you get a hsower of sparks. With a fuse, you'll open it. With the link, assuming you move the tool REAL FAST you can cintinue on. It is for sustained gross overloads, wverything else is individually fused anyway.
If you are of the instant off school, get a fuseholder and fuse from AutoSound or someone like - they're available up to like 200 amps or so. Pick up a spare too. When replacing fusible links, I always use wire nuts with springs inside which hold tension even when the link heats and cools. Crimps will loosen over time with temperature cycling. And the aire nuts are easier to mess with anyway :):)
--johnny
--- On Mon, 6/27/11, Dennis Sexton <dennisfsexton@aol.com> wrote:
From: Dennis Sexton <dennisfsexton@aol.com>
Subject: Re: [GMCnet] more A/C questions
To: gmclist@temp.gmcnet.org
Date: Monday, June 27, 2011, 4:36 PM
Jon wrote on Mon, 27 June 2011 10:21
> I wish I had more time to work on my GMC. I hate to bother everybody, but the gmcnet really makes the time I do have to work on it so much more efficient.
>
> I have a 75 palm beach.
>
> Dash A/C is not working. Was not too bothered, because the ONAN did work. and so did the roof air. now that thing quit running.
>
> Looks like my clutch for the A/C is not kicking in. I have jumpered the wires at the low charge cut off, and it is still not kicking on the clutch.
>
> Can i just hit the clutch with 12Volts at the compressor to diagnose if it is the clutch itself, or some other electrial switching problem for the clutch?
>
> this is a 7 to 10+ year sitting coach. so is there any knocking or cleaning of the clutch if it is having some problems? any shade tree mechanic way of getting it going without spending money? or before I have a sit down with the wife about finding extra money in the checkbook.
>
> Other question is the relay just up to the right from the isolator. there is a red-white wire. that to me, looks to come down, hook to a fusable link. and then go to the fuse panel. That fusable link wire gets pretty dang hot with the fan blowing/A/C switched on. I did not measure the amps, but it shows 14.7 volts with engine running. the fusable link looks to be slightly less guage wire then the red-white. and it has a crappy butt splice connection.
>
> before I replace that fusable link with a newer, better connected one... What should I be looking for with that wire, as not to have it burn up?
>
> also I know I should buy duracool and put that in, but I have a bottle of r-12. any thoughts/process as to adding oil with the r-12?
>
> I wish I had more detail, but my diagnose time is limited between work, wife, 2 kids.
Jon,
Can you safely put a meter on the connection to the compressor and chack that you have 12v at that point?
As for the roof air -- did it just stop? You might check the connections in the power panel -- known to become loose, low voltage/no air. Or is it running but not cooling?
If the ac system has not been opened there should be no real need to add oil.
Others need to input on the fusible link.
Dennis
--
Dennis S
73 Painted Desert 230
Germantown, TN
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Foolish Carriage, 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
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| Re: more A/C questions [message #132420 is a reply to message #132230] |
Tue, 28 June 2011 06:00 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Replace the fusible ink. They are are hanging ona card near the fuses and cost around $3.00 I have seen a lot of them deteriorated after 30 years and I have seen a few blown.
Yes you can put 12 volts direct to the compressor clutch and see if it moves. Just ground one of the electrical tabs and put an alligator clip jumper on the other. You do not need the engine running to check it this way and you won't get your fingers in the moving belt.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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