I had to head out of town for a two-hour drive today. Since the outside temps have been 104+ lately, I ran the A/C. On the way home, I decided to turn it off and recirculate the cabin air. After ~20 minutes, I noticed the air coming out of the vents was still cold, so I cycled the A/C button several times. There was no noticeable change in the air temp, or the engine response (usually, you can feel the compressor kick in and out), but the A/C light turned on and off.

I just got my '05 2500, so I'm still fumbling around a lot, but the A/C controls should be pretty mindless. Any clue as to what would cause the compressor to stay on? Would I get any diagnostic codes (I don't have a reader yet)?

Thanks for any pointers,

Joseph

On my 01 you have to turn off BOTH the A/C & the fan switch to stop the A/C from running.

I noticed the same thing yesterday after following a co worker down a dirt road. After looking in the owners manual, (I read it only when I really have to) I found that when you have the recirculate button on it turns on the A/C compressor to keep the windows from fogging up.