A/C blows hot air?

Thanks for the reply. The controller is no longer supplied by distributors. I will need to go to the wreckers and will get back to you.

The wreckers had a controller which I hooked up. All of the controls work but the A/C still does not work. The blower is still blowing warm air. Any suggestions? Thanks.

The A/C controller appears to be working correctly. When the A/C is turned on the compressor clutch engages. I am assuming the next step is to check the low-pressure system. Can the pressure be confirmed by using a small can of refrigerant? Also, should the low-pressure sensor be checked? I could not find this sensor on the low-pressure line. Thank you.

This pressure sensor is the only sensor visible for the system. It is located on a fitting attached to the condenser. The line from the compressor goes into the fitting at the top. A small line from the bottom of the condenser goes into the bottom of the fitting and then exits the fitting just below the compressor line. The sensor is located between the entry and exit points of the small line. It appears to be monitoring pressure on the line exiting the condenser.
What are your thoughts as to the problem and what to do now?

New information: I was just inspecting the A/C system and the compressor clutch did not engage. After turning the car off and on and the AC control off and on the compressor clutch is now engaging. The high-pressure line entering the dash feels cool but not cold. The line from the compressor to the condenser is very hot (too hot to hold a touch).

The low pressure was about 20 PSI before adding refrigerant. One can of refrigerant brought the pressure up to about 28. The system seemed to be running perfectly, blowing cold air. But thinking the pressure needed to be about the middle of the blue zone (35 PSI) I added more until the pressure was 35 PSI. The compressor started making noises (continuous groan) and was cycling on and off. Using the gauge hose, I bled the pressure back to about 30 PSI. The system cycling stopped but the compressor is still making a noise. Other than the noise everything seems to be working great. Should I bleed more off to quiet the compressor? Is there something else you'd suggest?
Sorry, but I don't have a high-pressure gauge. The compressor appears to turn on normally when the ac control is turned on.

After letting everything rest overnight, I turned the A/C on, and it all seemed normal. Cold air at the inside vent was 36F. I let the system run until the engine was hot, and the compressor started making the noise again. This indicated to me that the pressure in the system was too high when hot. I bled a little more out of the system and all seems well. Let it cool down and started again the next day. Compressor quiet and air cold. All seems well now.
Thank you for your help.