i have a 05 fx4 and have some kind of noise comming from my a/c. its hard to describe. kinda like a wooshing sound that comes and goes, maybe like a compressor comming on and off. is this sound normal?

 

If your A/C is ice cold, everything is probably OK. How loud is the whooshing? Can you hear it over the radio?

 

Not directly related to this particular question but was wondering if the AC on an 06 Supercrew could cause a click or arcing noise by water condensing on the unit and dripping on the hot exhaust pipe. Had the AC on with the windows rolled down tonight and head the noise like a click or zap from underneath the truck. Later with the AC off and windows rolled down ther was no noise. Any one else experienced this?

 

I heard it once the truck was off for about 2 minutes facing downhill slightly, and I was standing by it. Definetely water dripping on something hot. Exhaust?

 

I've got the same truck you've got & had the same problem. Took mine back to dealer & the air compressor was replaced along with some other things. Do a search on it or look for my post. I posted exactly what they put down on the repair bill of what work they did.

 

I also noticed the same the same thing after shutting one of the front doors, it seems like something drips on a warm surface..