Alright, my buddy and I installed a new ac system minutes the evaporator core. New lines, pressure switch, compressor, condenser, expansion valve. Did a vacuum for a hour, let it sit for a additional half hour to check for leaks. Didn't drop pressure at all. Go to add freon and the compressor won't cycle. Low pressure it's around 50 and high is at 40. I pulled the AC compressor relay from under the hood and over rid it with a paper clip just to see if the clutch would engage and it did. Put a brand new relay and still nothing. Replaced the 10 amp clutch fuse and nothing. And I only tried these things cause the pressure didn't change after trying to charge it for 20 minutes and the compressor wouldn't cycle and the pressure on high or low side wouldn't move. Any help would be greatly appreciated.