Automotive Air Conditioning Information Forum (Archives)

cs386546 on Sat June 01, 2013 12:13 PM

Year: 2000
Make: chevrolet
Model: 1500
Engine Size: 5.3 lite
Refrigerant Type: 134
Ambient Temp: 90
Country of Origin: United States

I have a 2000 Z-71 Chevy truck and the A/C cycles off and on. Sometimes it will run for days without quitting and some days it cycles on and off. It blows really cold air when it is working. It seems to me when it quits if you turn it off for a few minutes it will start working again. Sometimes it will stay working but yesterday it did it constantly. It also seems to me the warmer it gets outside the more it does it. Can any one help me?

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Steven A Cirtaus

GM Tech on Sat June 01, 2013 3:50 PM

Sounds like evaporator freeze up- next time it quits- see if compressor is running and/or suction pipe is frosty white- if frosty- then freeze-up- you can't blow air through ice! So if frosty- the fix is a new cycling switch- because that is what controls evap from freezing.

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

MrBillPro on Sun June 02, 2013 12:11 AM

Quote
Originally posted by: GM Tech
the fix is a new cycling switch- because that is what controls evap from freezing.

So are you saying it's normal for a perfectly charged a/c, to cycle on and off if cabin temps get low at high rpm? Tim and I emailed back and forth about this today, my 98 GMC will freeze you out, I weighed in the charge, set the adj. lpco @21 psi and when the cabin cools down it will cycle at high speeds. I told Tim, I cringe just thinking about going down the road at 1600 to 2000 rpm's and the compressor cycling on and off on a 5 hr. trip, the clutch must be screaming, or is this normal right out of the factory?

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Don't take life seriously... Its not permanent.

Edited: Sun June 02, 2013 at 12:12 AM by MrBillPro