A/C Suddenly Blows Hot Air!

[JimG]

Naturally when you really need it! Today the A/C suddenly blows nothing but hot air.

What I've found so far:

Compressor is not engaging, but you can turn it by hand easily.
Aux fan not working but have 12v across the large wires. It seems that unless something else controls the fan it is bad.

However,From researching other posts on this website I found that it seems that it could be the AUX fan or the Compressor clutch.

How can I be sure before I spend the big bucks?

[SlickGT1]

Take it to an AC shop and have them check refrigerant. You might be low. Compressor won't turn on with low freon.

[JimG]

Checking around I found:

1. Refrigerant around 100psi
2. Clutch not engaging however, normally 5v to coil with 12v pulsing it every 30 sec or so.
3. If I disconnect the pressure switch that is near the compressor the Aux fan turns on.

What would make the refrigerant pressure so high? Car has not been worked on.

Could this be prevent the compressor from engaging?

[mike_dmt]

Originally Posted by SlickGT1

Take it to an AC shop and have them check refrigerant. You might be low. Compressor won't turn on with low freon.

+1

[bumere90]

Did you ever figure out the problem? I am having the same problem

[Jeffatpm]

It'll be high when it's not running(compressing), when it's running it'll pull the low side down around 45PSI-ish.

[JimG]

It was the compressor clutch