Auto Air Conditioning & Heater Repair: 1997 Blazer compressors works but air hot, vacuum pump, atmospheric air

Question
I have a 1997 Blazer S-10. The ac compressor is running full time but none of the lines are cold and no cold air coming out of vents. Just got this vehicle and have made no repairs to system b4 my question to you. Thanks

Answer
You need to put a set of A/C gages on the system to see what your high and low pressures are at BEFORE you go trying to add freon.

Possibilities are:

Restricted orifice tube.
System needs to have the old freon removed, the orifice tube replaced, the system evacuated of all atmospheric air via a vacuum pump and then have new freon installed.