92, 124, 2.5 turbo diesel air problem

[epssax]

My auxliary fans do NOT come on. When I run 12 volts straight to them they run. I have checked fuse in fuse box, checked heavy inline fuse on drivers fender wheel. There is 12 volts at both sides of these fuses. When I short the two wires leading to the high pressure switch they do NOT energize the fan, either. I checked the voltage leading into the high pressure switch and it is very low. Test light was very dim! I can't remember the last time the fans ran. All I know is that I can't get my air conditioner pressures correct until these fans run. I am not getting much cooling(almost none) and there are lots of bubbles in sight glass. The pressures are low/24 and high/275. However, they are not good readings because the fans are not exchanging heat on the high side of the freon circuit. This is a 134A system. I just replaced an expansion valve. Several on-line manuals don't cover this and I have searched this site for an answer. Thanks in advance for your reading this and possibly giving me an idea or two to check out! Ernie in Louisville