So i replaced every component of my a/c system(evap core, heater core, condenser, orifice tube, compressor, lines, etc.) I charged up the system with some freon and when I went to turn the a/c on it only blows hot air, and all the time whether the a/c is on or off. I know that this has to be a blendor(sp?) issue so I checked it and sure enough the door doesn't seal shut all the way. So i figured I would put a manual shut off valve in the heater hose line that circulates into the heater core and it should blow cool since it wasn't recieving any hot coolant. Wrong! It's still blowing hot air all the time even with the valve shut completely. Any ideas/suggestions. I'm tired of burning up in my car

 

anyone?

 

First thing to check, is the compressor actually turning, look at the center of the front pulley on the compressor, it has to turn. If so, feel the aluminum receiver/dryer tank just in front of the AC box under the hood, it should get real cold and sweat from water condensing on the outside. If all this is happening, you may have an airlflow diverter dashpot not working right. Some of those are really hidden in the dash too.

 

Bad pressure switch maybe.

 

Yeah I checked to make sure the dryer tank was cold and sure enough it's a block of ice. I also stuck a thermometer into the evap core box and it's reading around 45 degrees on the inside so I know everything is functioning properly. And yes the Compressor clutch is engaging properly as well.

 

Next thing to check would be to see if you have vacuum to the controlls. Put the fan on high and put the AC into the max position, should hear it get much noisier when the door opens, then try the defrost setting, air should go to the windshield. If this works you're pretty much down to one air door operator I suppose that's holding the cold air out of the system.