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[GMCnet] AC Troubleshooting [message #83679] Sat, 08 May 2010 16:14 Go to next message
George Zhookoff is currently offline  George Zhookoff   United States
Messages: 398
Registered: December 2004
Location: Snellville, GA
Karma: 6
Senior Member
Hello all!
I'm trying to get my dash air to work. Jumped pressure switch. Power all the way to ground thru the ac clutch. Hot on both sides of the clutch electrical plug. Test light on from + side of plug to ground and test light on from - side of plug to ground. Power is going thru clutch but clutch does not engage.

My take is that the ac clutch is bad. What do you guys think and what are the next steps? More testing or go for a new clutch?

Thanks
George Zhookoff
78 EL II
Atlanta

PS. Burned coach now resting peacefully @ Zeb's: rear single muffler heat started fire. Scary to look at!
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Re: [GMCnet] AC Troubleshooting [message #83687 is a reply to message #83679] Sat, 08 May 2010 16:47 Go to previous messageGo to next message
Jon payne is currently offline  Jon payne   United States
Messages: 495
Registered: May 2008
Karma: 1
Senior Member
Replace the clutch. I changed the bearing out on mine last year. The whole job only took a few hours. While you are at it you might as well replace the bearing since after the clutch removal the next item to come off will be the pulley which of course houses the bearing.

I got the bearing at Rockauto.com.

Jon

http://www.gmcmhphotos.com/photos/showphoto.php?photo=29605&title=ac-clutch-bearing-r-2fr&cat=5194


Jon Payne
76 Palm Beach
Westfield,IN
Re: [GMCnet] AC Troubleshooting [message #83693 is a reply to message #83687] Sat, 08 May 2010 17:16 Go to previous messageGo to next message
Craig Lechowicz is currently offline  Craig Lechowicz   United States
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
Senior Member
George wrote:
>Power all the way to ground thru the ac clutch. Hot on both sides of the clutch
>electrical plug.

George,
If the test light lights from a good ground to both sides of the a/c coil connector, you don't have a good ground for the compressor wiring. Sort of a simplistic way to think of it, but power comes in the + side is "used up" going through the coil and should be at 0 volts on the ground side if the ground is good.


Craig Lechowicz
'77 Kingsley, Waterford, MI
Re: [GMCnet] AC Troubleshooting [message #83724 is a reply to message #83679] Sat, 08 May 2010 21:02 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
Before you tear it out, use a VOM and Ohm across the 2 clutch terminals. Im not sure the value (I guess I could go out the the garage and Ohm one out) but the thing should not show as 'open' circuit. Make sure short the ground little wire is not bad right at the grounding lug. It can be broken inside the insulation and still look good. Our wires are OLD. Give it a tug and if if stretches right off you found the problem. Hot on both sides of the clutch means there is NO GROUND.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] AC Troubleshooting [message #83725 is a reply to message #83679] Sat, 08 May 2010 21:04 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
PS To OHM the clutch pull the plug and test the compressor out of circuit.
Then ohm the ground side of the loom plug to ground and it should be 0.


John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] AC Troubleshooting [message #83801 is a reply to message #83679] Sun, 09 May 2010 16:00 Go to previous messageGo to next message
George Zhookoff is currently offline  George Zhookoff   United States
Messages: 398
Registered: December 2004
Location: Snellville, GA
Karma: 6
Senior Member
Couldn't find any of the 5 or 6 VOMs I have. Son in laws ya know!
So I jumped DC to clutch spade connector and jump other spade to ground. Clutch kicks in and out with power.
You're right, poor / no ground.
See if I have time to work on it. Have to fire up the rotissere for an eye of round. Kids and grandkids/ babies headed this way!
Thanks,
George Zhookoff
78 EL II
Atlanta
PS to Jon Payne, I've studied your album on clutch replacement in case. Thanks!

----- Original Message -----
From: gmclist-bounces@temp.gmcnet.org <gmclist-bounces@temp.gmcnet.org>
To: gmclist@temp.gmcnet.org <gmclist@temp.gmcnet.org>
Sent: Sat May 08 22:02:08 2010
Subject: Re: [GMCnet] AC Troubleshooting



Before you tear it out, use a VOM and Ohm across the 2 clutch terminals. Im not sure the value (I guess I could go out the the garage and Ohm one out) but the thing should not show as 'open' circuit. Make sure short the ground little wire is not bad right at the grounding lug. It can be broken inside the insulation and still look good. Our wires are OLD. Give it a tug and if if stretches right off you found the problem. Hot on both sides of the clutch means there is NO GROUND.
--
John Lebetski
Chicago, IL
77 Eleganza II
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Re: [GMCnet] AC Troubleshooting [message #83807 is a reply to message #83679] Sun, 09 May 2010 17:37 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
I love fixing stuff without me actually having to touch it! Something about that wire type with age and flexing--- it breaks inside the jacket. I went through that with the wire to the washer pump when first got my coach. No 12V. I found a bad spot, cut it out, soldered and heat shrunk it and much to my surprize, it didn't work. That same wire was bad in 3 places total so I cut it back as far as I could and spliced in a new section. Has worked ever since.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] AC Troubleshooting [message #83816 is a reply to message #83679] Sun, 09 May 2010 18:16 Go to previous message
George Zhookoff is currently offline  George Zhookoff   United States
Messages: 398
Registered: December 2004
Location: Snellville, GA
Karma: 6
Senior Member
Well. Added 2 cans of HC12A, ran for a few and cold air!
Whoo ha!
Thanks everyone!

I did find a VOM, clutch metered at 4. Something ohms.

Thanks again,
George Zhookoff
78 EL II
Atlanta

----- Original Message -----
From: gmclist-bounces@temp.gmcnet.org <gmclist-bounces@temp.gmcnet.org>
To: gmclist@temp.gmcnet.org <gmclist@temp.gmcnet.org>
Sent: Sun May 09 18:37:36 2010
Subject: Re: [GMCnet] AC Troubleshooting



I love fixing stuff without me actually having to touch it! Something about that wire type with age and flexing--- it breaks inside the jacket. I went through that with the wire to the washer pump when first got my coach. No 12V. I found a bad spot, cut it out, soldered and heat shrunk it and much to my surprize, it didn't work. That same wire was bad in 3 places total so I cut it back as far as I could and spliced in a new section. Has worked ever since.
--
John Lebetski
Chicago, IL
77 Eleganza II
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