[rreale]

my 2013 camaro ss, is having some a/c issues:

1 year ago a/c was not cold enough, compressor was hard to spin manually, got a new compressor and it was ice cold last summer. Last month my a/c was just blowing cool, again the compressor was hard to spin, swapped it out under warranty. 1st day out it was blowing about 48-53 degrees on a 74 degree day. yesterday it was nice and cold on a 82 degree day. but later when it was 85 it got warm again. sometimes turning it on/off seems to help it blow cold again. yesterday on a 4 mile ride it blew anywhere from 50-72 degrees.
when i looked at compressor yesterday it was engaged for a long time., engine temp was 201, both radiator fans were running, removed the cabin filter, tried a different a/c clutch relay.
my mechanic said the ac gauges read perfectly when he charged it(he has changed a compressor in a previous vehicle)
I have seen the threads on the blend door, but i can switch it to defroster ok and on a 70 degree morning i am able to make the cabin comfortable and not too cold. any ideas