A/C clutch not working?

Tiny
89SIGO
  • MEMBER
  • 2000 CHEVROLET SUBURBAN
  • V8
  • 4WD
  • AUTOMATIC
  • 167,000 MILES
Last fall my A/C compressor seized up. I removed the belt from the A/C Compressor and drove it through the winter since here in Minnesota, A/C is provided by nature from Oct -April. I just replaced the A/C compressor + new serpentince and new A/C belt. Chraged up the system, added A/C oil too and the clutch will not enageg when the engine is running and the A/C is turned on. I checked a few fuses but no luck there. What do I check next?
Thursday, May 13th, 2010 AT 8:31 PM

10 Replies

Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Lets start by checking for power at the pressure switch and then at the clutch itself, Also lets check for ground of the clutch as well this guide will help us.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please run down this guide and report back.
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Saturday, May 15th, 2010 AT 10:01 AM
Tiny
CERECERELY
  • MEMBER
  • 1 POST
  • CHEVROLET SUBURBAN
1999 Suburban, 33K miles. The AC clutch doesn't engage. Checked fuses 1 interior OK, One in engine compartment OK. Swapped identical relay in engine compartment, no change. No current at AC clutch plug.
No clutch engage when jumping from battery to prongs on clutch assembly. Added about 1/2 can of gas, while engine was running but compessor was not. It appears that there are two problems. The clutch not engaging, are the prongs + and - or is it internally grounded? Why no current at the engine side of the plug?
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Check the low pressure switch on the accumulator. Jump the connector and see if the compressor will run, do this only briefly so you don't burn out the compressor! Be ready to charge the sysem then jump the switch.
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
ANNACRAWFORD
  • MEMBER
  • 1 POST
  • 1997 CHEVROLET SUBURBAN
  • V8
  • 2WD
  • AUTOMATIC
  • 197,000 MILES
Trying to take off clutch with puller and when I go to take it off the pulley bends and sems like it wont pull off shaft
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
OBXAUTOMEDIC
  • MECHANIC
  • 3,711 POSTS
If you are using a regular 2 or 3 jawed puller you are using the wrong tool for the job....

What you need is an A/C Clutch Removal and Installer Tool.... Similar looking to the pic below....


https://www.2carpros.com/forum/automotive_pictures/188069_gmacclutchpuller_1.jpg

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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
TOMALTACH
  • MEMBER
  • 1 POST
  • 1994 CHEVROLET SUBURBAN
  • V8
  • 4WD
  • AUTOMATIC
  • 127,000 MILES
1994 Suburban LT 4x4 127,000 miles

Based on the noise coming from the compressor and the amount of reddish-brown dust in the engine compartment, I believe the compressor clutch is toast.
Currently I don't have the cash to replace the compressor. Can I switch to a smaller serpentine belt and bypass the compressor pulley for now? If so, how do I determine what size belt to purchase.

Finally, is it possible to buy a kit and/ora new clutch an rebuild these compressors?

Lost the compressor on my first car, 1973 Buick Century. I pulled the v-belt and rolled down the windows.
Change isn't always progress.
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
2CARPRO JACK
  • MECHANIC
  • 11,533 POSTS
Not sure if the belt will work like that without some kind of idler pulley to take its place. If just the bearing is bad on the compressor, you can buy that seperatly and it doesnt require the system be evacuated. You will need the puller for the clutch and snap ring pliers to replace it.
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Get a junk yard compressor and swap the clutches, It worked great for me. Or you can buy a/c eliminator pulley. Probably cost about the same!
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
RUDYCAT
  • MEMBER
  • 3 POSTS
  • 1994 CHEVROLET SUBURBAN
  • V8
  • 4WD
  • AUTOMATIC
  • 189,000 MILES
How can I tell if I need to replace the clutch, or just the pressure switch?
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Tuesday, August 11th, 2020 AT 5:02 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
On many systems, the compressor will not turn on if the refrigerant is low because the "low pressure safety switch" prevents the compressor clutch from engaging if system pressure is low. This protects the compressor from possible damage caused by a lack of lubrication.

One of the first things you should check, therefore, is compressor engagement. If the compressors magnetic clutch is not engaging when the A/C is turned on, the problem may be a blown fuse or a wiring problem. If the fuse is blown, replacing it may restore cooling temporarily. But the underlying reason for the fuse blowing in the first place needs to be identified and corrected to prevent the same thing from happening again.

If the magnetic clutch is receiving voltage but is not engaging the compressor, the clutch is defective and needs to be replaced. If there is any evidence of leakage around the compressor shaft seal, the seal should also be replaced.

If the clutch works but fails to turn the compressor (the belt may squeal in protest!), The compressor has seized and needs to be replaced.
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Tuesday, August 11th, 2020 AT 5:03 PM (Merged)

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