Author Topic: AC Compressor cycling  (Read 2272 times)

Offline jsc

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AC Compressor cycling
« on: March 19, 2021, 05:21:43 AM »
Hi!  I've got an '83 C10, which just came out of the shop after having some carb and exhaust issues.  But now my AC compressor is "cycling" on regular intervals, about every 5 seconds.  I can hear it click from inside the cab, and I can watch it cycle on and off when I'm under the hood.  AC is not blowing cold, even though it was before it went into the shop.

Any thoughts?  It always frustrates me when I put a vehicle in the shop, only to find a new problem when I get it out.....

Thanks,

John

Online Rapid Roy

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Re: AC Compressor cycling
« Reply #1 on: March 19, 2021, 06:19:18 AM »
Usually low on freon.
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Offline JohnnyPopper

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Re: AC Compressor cycling
« Reply #2 on: March 22, 2021, 10:17:46 PM »
The Rapid One is correct...

Was your AC solid before? Had you serviced it recently?

Do you regularly use this shop?

I know I , too many questions but you/we need to start somewhere before making aSSumptions.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Mike81K10

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Re: AC Compressor cycling
« Reply #3 on: March 22, 2021, 11:06:18 PM »
Don't use your A/C until it is serviced. Being low on freon can damage the compressor. If you have a leak, you can lose oil as well. Try to see if you can find a leak.
« Last Edit: March 22, 2021, 11:10:06 PM by Mike81K10 »
"Tell me and I forget. Teach me and I remember. Involve me and I learn." -Benjamin Franklin

Offline JohnnyPopper

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Re: AC Compressor cycling
« Reply #4 on: March 22, 2021, 11:16:42 PM »
Good call by Mike.

Look for oil leaks around the tubing/fittings, not hard to spot.

1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline jsc

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Re: AC Compressor cycling
« Reply #5 on: March 25, 2021, 05:22:45 AM »
Thanks.  Yes, I've used the shop before.  And yes, it was running correctly before I put it in for service.  It's sat in my garage since, so I haven't run it. 

I guess I was wondering if it could be electrical at all.  Squarebodies usually have some demons electrically, 

Offline JohnnyPopper

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Re: AC Compressor cycling
« Reply #6 on: March 25, 2021, 11:21:23 AM »
One good thing the factory did was install a pressure sensor, that when too low, will not allow 12v to go to the compressor magnetic clutch.

Could just be coincidence that the gas went low after the visit. You can buy refrigerant with a pressure gauge and tell right away. If you're in Cali (too bad for us) the can will cost you a refundable 10.00 when you bring it back (Within 30 days!) 
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline jsc

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Re: AC Compressor cycling
« Reply #7 on: March 25, 2021, 08:41:27 PM »
Thanks.  I'm feeling better about it all

Offline JohnnyPopper

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Re: AC Compressor cycling
« Reply #8 on: April 29, 2021, 10:37:08 PM »
So what ever happened?    ???
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction