A/C continues to run with "Vent" selected

[Edahall]

Vehicle: 1990 Suburban

Several days ago as I was driving, I noticed that very cold air was coming out of the vents even with "vent" selected on the controls. I started investigating and the A/C compressor is now stuck on with "vent".   However, the A/C compressor does disengage when "heat" is selected on the controls.

How can I fix this problem?

[DrDaryl]

On mine it was the "AC actuator switch" located on the climate control unit--had a hole burned through it and the compressor ran all the time--might help.

[Edahall]

On mine it was the "AC actuator switch" located on the climate control unit--had a hole burned through it and the compressor ran all the time--might help.

Thanks,  I bet this switch is the culprit on mine as well.  Maybe it's out of adjustment or needs cleaning.

[Project86]

I also had this and found a hole burned through the actuator switch. Replaced it with a new one from Auto Zone, problem solved!