new to forum need ac help please

[scrappergirl]

hello all

i have a 94 gmc sierra and again this year my ac is blowing both cold and hot air. it will work for 10 minutes then blow hot air until i turn off for a while then when i turn on again it will work for 5 or ten minutes then go off again. .My ex who was a mechanic did something to it -(no idea what) last year and it has worked fine since Im not a mechanic by any means but don't have a lot of money right now to take to a shop. i have several cans of 134a if i have a leak and leak detector oil but i have no idea what to do with any of it or how to check for leaks in the system

. Any ideas are graciously appreciated!!

[BoostedMA70]

You may want to hook up a guage to it and see what it reads. It sounds like it's overcharged. aI have mine at 35psi and it blows ice cold. I had a customer come in recently with the same issue and his low side was at 75psi! It was causing the compressor to lock up and not pump and Freon through the system at all

 

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[scrappergirl]

thank you i will do just that

[Jeep_Comanche17]

what BoostedMA70 is probably your issue, but the clutch might be worn as well. start the truck, put the a/c on max, pop the hood and watch the pulley on the compressor. if the clutch is worn it will rattle, or not spin. it also wont spin if it is low on freon to keep the compressor from burning up.