Since the 1480's used York, alum. A bad short to one of these could burn it out and seeing how as the combine uses many of these little items, finding the right one can be a real nightmare. Again, one more note. It was pointed out to me that an incorrect clutch air gap could also cause this problem. Just another reminder that one must check all of the basics first.
A.Your question is a little bit tricky.
Especially when talking about farm equipment. Your hi side pressure is what will give you the most info pertaining to the system charge. Hi side pressure is directly relevant to ambient temperature. This assumes that there is no blockage in the system or the condenser. Here is where things get a little tricky.