Hi guys,
I've recently changed a bunch of parts on the benz to get the A/C going. I replaced all the hoses, orings, drier, condenser and aux fans. I evacuated the system and charged the system. The compressor was running fine as I was charging the system but stopped when I reached a clear sight glass. I checked the terminals going to the compressor and dont have any power. There are three terminals on the compressor so I don't know what the third one is for. There is some sensor on the back of the compressor and the wires go to the compressor terminal block. I thought maybe it's a temp sensor for the compressor. I checked the pressure switches on the drier. The red one brings the fans on. The other one is closed and I assume it's either a high pressure switch or it's used to cycle the compressor. I thought maybe someone could point me in the right direction. The car is a 1990 300D with the 2.5 L

Thanks