AC not blowing cold air at all. It is blowing as it should but just not cold air. Bought one of those self help recharging kits. The compressor comes on when it is supposed to. When checking pressure guage on kit prior to filling it was in the red, (way too high). Released air from Hi side and rechecked gauge. Gauge dropped more and more as I continued to let out air. Got the gauge back into the normal pressure range. Just let the cat run and the gauge started climbing again. Did not continue. did not add anything from recharge kit. If not compressor, then what could be some of the issues. I have been reading about blower door etc. Just can't figure out why pressure so high and when I got it back to normal pressure still no cold air.

 

The compressor clutch must be engaged and the engine running in order to allow for proper low side pressure readings. Whenever the compressor clutch disengages, the pressure in the two sides (low & high) of the system will equalize.

If your system pressure is too low or two high, the clutch will disengage. There are sensors on each side of the system that control the clutch.

If the low side line is getting cold while the compressor clutch is engaged, then I would suspect a problem with the temperature door inside the truck. Air always flows over the A/C core, but a door controls whether the air also flows over the heater core. You could be cooling just fine, but the heater core is warming the air right back up...

To assist further, you really need to post details about your truck. Year & HVAC controls (manual - red/blue around the temp **** or automatic - numbers around the temp ****) please.

 

Thanks. It's a 2002 auto climate. I see and hear the compressor engage while engine running and ac turned on. Whether that means it is working I am not sure. Another note. The car has the heater bypass done on it as the heater core earlier this year year. AC was not working before the bypass was done. I hope this helps. I am stumped. Should I try the jumper procedure to check something ? Thanks.

 

Are any of the lines getting cold (low side) or hot (high side) when the compressor is engaged? How long does the compressor run for?

 

I would suggest you do some reasearch on how auto a/c works. The principles of it. Google it. When you said you let "Air' out of the high side, I can tell you need to do a little research. What you let out was refrigerant. If there is air in the system, obviously it wont work.

A/c works on the principle of compressing a gas raises its temperature. Lowering its pressure lowers it temperature. In a normally working system, one side is high pressure/high temperature and the other side is low pressure/temperature.

Please dont jumper anything out. Those pressure controls are safeties and allow for the proper operation of the compressor. The LPC will cycle the compressor on and off according to system load and pressure. The HPC should never actually activate. It is a safety only.