A/C Compressor always ON

[InTheAir]

I've noticed that my A/C compressor appears to be always on no matter what position the climate control knob is in, except for OFF (when in OFF, the compressor is also off; in every other position, the compressor is on).

It blows cold in all settings and I can hear the clicking of the compressor cycling intermittently on/off.

Any ideas what could be the cause???

 

[InTheAir]

Ok, a little of my own google-foo at mysporttrac.com....

This is from the shop manual.

MAX A/C - The compressor will operate if the outside temperature is above 43 deg. F.
A/C - The compressor will operate if the outside temperature is above 43 deg. F.
PANEL - The compressor is off.
OFF - The compressor is off.
PANEL/FLOOR - The compressor will operate if the outside temperature is above 43 deg. F.
FLOOR - The compressor is off.
DEFROST - The compressor will operate if the outside temperature is above 43 deg. F.

 

[BigGreenV10]

ok didn't know that thanks for a little info

 

[429CJ-3X2]

The compressor on our '93 Aerostar would cycle on and off like that, most noticeably between 40 and 55 degrees or so. You can really feel it in an Aerostar as the engine surges when it turns off. Well, the engine doesn't surge, but it feels like you're going in and out of wind gusts. I thought something was wrong until I read similar info as InTheAir stated on one of the forums.
My '94 Explorer does it too, but it's only noticeable at about 35 mph and in a narrower temp range.