I am having no issues, but for education purposes want to put eyes on where the D2 air governor is located on a 2003 U320 ISM.
Access from under bed hatch, or from under the coach? My current camp site the rear is all the way down for level, and unable to follow the air dryer hoses as parked.
Open the rear engine access door on the back of the coach. It's located on the top of the compressor on the right side of the engine behind the a/c compressor. That's how I see mine. Also that's how I replace it. Hope this helps.
From the back of coach, looking forward. It will br on the passenger side of eng., in front of and below the AC compressor. That's where mine is.
It's covered with a black cap