My GMC Sierra A/C blows cold then Hot

[Jillermeister]

I have installed a new A/C compressor, Clutch, evaporator, tube the works. New one was defective and immediately exploded inside when A/c kicked in.  I had to again to replace the entire system .  I bought a name brand instead of Advance Auto brand and installed it. I then took truck to a reputable garage to have entire system cleaned out of all metal fragments and then recharged.  My A/C then began to blow cold and then hot air.  Garage installed a blender door actuator.  When picking up my truck, I was told the heat door didn't completely close, so I was getting a blend of warm air with the cold.???  Anyway, it worked but was not really very cold.  A year in and now the truck blows very cold, then switches to very hot air.  I tried to recalibrate the actuator, but I still am having this issue.  Any suggestions?  It is a 2001 but there was not a topic for my year of GMC and 1999-2003 are supposed to be the same.

[txab]

Does it go from hot back to cold? If you shut the vehicle off and restart it , does it blow cold again, if so it's another actuator

[Jillermeister]

I don't know, but I will check this out.

 

[richard wysong]

Did they install a filter on the suction side of the compressor? possibly it is clogging with the remaining debris or the orifice tube is partially clogged

Edited May 18, 2025 by richard wysong

[Jillermeister]

They should have done it correctly.  They are a very good mechanic garage.  I have fair mechanic experience and have talked with them.