I have a 99 suburban. My a/c died on me last week. I had all new (not rebuilt) compressor, drier and expansion valve put in. But it doesn't get any colder than 58deg if the rear air is off and if it is on the temp jumps up to almost 70 deg. I know its been hotter than hades here (105) but shouldn't the air be colder and the whole suburban cool off with the front and rear air on? :?