The ac compressor on my 96 dakota v6 turns on randomly. It is winter and i really don't need the ac to be turning on. For example the other night: A long drive on the highway, about 40 degrees and the ac compressor come on. The ac button is off and i had the heat on. When I got home I opened the hood and it looked like the north pole on the ac lines, they were all covered in snowy ice. Whats going on? And then sometimes when im idling, I'll hear click under the hood and the compressor will come on. Its hard to trace the problem because it never happens when im under the hood with the logic tester trying to figure out whats wrong.

 

i would start with the switch. maybe disconnect it and if it still comes on like you described then most likely a short before the switch. if it does not happen with the switch disabled then maybe the switch is shorting.

 

The AC comes on with the heater system to dehumidify the air it helps to prevent fog from building up on the windows.

 

So it's supposed to do that?

Also, I am just noticing this as wee came upon winter. I never noticed durring summer. And also, even when the heat isn't on, it will just come on.

 

It should come on whenever your heater control is set to defrost. If it bothers you, just unplug the clutch for the winter.

 

+1 to the defroster posts. i broke the one in my intrigue a while ago so it doesn't come on anymore when the defroster is on but will turn on when the ac button is pushed. its a pain the rear when we get a wet heavy snow because the windows fog up even though the car is warm, unless i turn the ac on with the defroster.