AC issues

[Brannan73]

I have a 2017 Mustang Gt Premium 70k miles. So I bought my car at about 22k mile, when I bought it the AC was always cycling weird. Cold one minute then blistering hot. I turn it off for 10 minutes and back on it runs fine for 5 minutes. Cold. Eventually the compressor went completely out because the compressor belt was missing and it was locked up. So I replaced it. It blew cold the day I put it in but the temperature outside was 55. Today it’s 85 out and it’s back to doing the same thing. Cycling cold for 2-7 minutes then back to hot or maybe a room temperature. Any ideas?

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[ORRadtech]

Take it to a good mechanic or someplace that specializes in auto air and let them check it out.
The most likely thing is a low refrigerant charge but there are at least 3 or 4 other things it could be.
Unless you have a set of manifold guages and a modicum of ac knowledge having a professional check it is your best bet.
Edit, just reread your post. You replaced a locked up compressor? Did you replace anything else? Did you flush the system? Did you vacuum down the system? It's entirely possible that you have damaged the new compressor.

 

[Brannan73]

Take it to a good mechanic or someplace that specializes in auto air and let them check it out.
The most likely thing is a low refrigerant charge but there are at least 3 or 4 other things it could be.
Unless you have a set of manifold guages and a modicum of ac knowledge having a professional check it is your best bet.
Edit, just reread your post. You replaced a locked up compressor? Did you replace anything else? Did you flush the system? Did you vacuum down the system? It's entirely possible that you have damaged the new compressor.

I did not replace anything else. The system was flushed vacuumed and checked for leaks after installation

 

[Brannan73]

I did not replace anything else. The system was flushed vacuumed and checked for leaks after installation

Well other than the compressor belt.

 

[MiamiGT350]

I would put a digital pressure gauge on the high-side recharge port, which is located on the top passenger side, by dash.

If you put the AC on max-cold, you should be able to see the compressor spinning in the lower left, front of the engine bay. Does it seem to stay on, or is it starting and stopping at random? Is there any correlation between the pressure reading and whether the compressor is on/off?

Basically, I'm asking you if it's cutting off when the pressure drops (< ~20psi), or when the pressure gets too high (> ~40 psi)

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