YACT: Problem with Air Conditioning

[cchen]

Something is wrong with my a/c. I press the button, rpm's drop, but hot air blows out. I looked under the hood and the compressor is on. Tried refilling with freon, still hot air blowing out.

What could be wrong here?

 

[notfred]

Maybe you have a leak.

 

[cchen]

How could I check for that?

 

[Drakkon]

get some of the uv charge and a blacklight...charge it...let it run for a few mins (at ngiht would be easiest) bring out the blacklight...and find ur leak

**This can only be done with 134A refridgerant btw ***

What you wanna look for

 

If the compressor is turning, the freon charge is fine, (All Motorvehicle A/C systems have a low pressure cut off switch which saves the compressor should the freon leak out), most likely you have a stuck heater duct door or a plugged accumilator/reciever/dryer.

Start up your vehicle, turn on the A/C, carefully touch the large and small hoses running to and from the compressor, the small diameter pipe/hose should be very hot while the larger diameter pipe/hose should be frosty cold, if this is the case, you have a stuck air door inside the heater box, if this is not the case, you have a plugged accumilator/reciever/dryer.

 

[Quixfire]

Depending on the car you could also have a stuck heater valve allowing coolant to flow through the heater core heating the cooled air.

Please post you make, model and year.

 

[cchen]

i have 1990 mazda miata

here's some more info - i just drove with the a/c on, the air that came out was significantly cooler than with the a/c off
another thing, this happened a while ago, the a/c was left on a while ago, and my mechanic said it caused some belt to break.... not sure exactly what happened there as i was still away at school...

let me know what you guys think

its too damn hot without the a/c

 

[cchen]

bump

 

[Quixfire]

Sounds like a restriction in the system, you should have a qualified mechanic look at and perform a performance test.

I would need pressure and temperature reading to diagnosis further.