Our 2000 Durango makes a buzzing noise under the hood only "when the air conditioner is on and under acceleration". Once out of the lower gears (near cruise speed), there is no buzzing sound. Is this a solenoid of some type starving for freon?? A couple of years ago we had the compressor go out and replaced all associated components. It never has blown very cold, I even insulated the cold lines after replacement. We haven't had the freon checked since R & R, perhaps it's getting low for some reason, I hope that's all it is. Any suggestions on the buzzing?? Thanks!

 

On the 'never has blown cold' part - you might wanna check this thread.

https://dodgeforum.com/forum/1st-gen...-problems.html

Was looking for something different, but just ran across it before I see your post here.

 

It could be the loading of the motor causing excesive torque on the pulleys, have you looked at the tensioner pulley yet?

Also you could check pressures, but I think it's fine.