I can maybe explain the 3 potentiometers on the chip under radio. The biggest one is for steering, you will calibrate so the groomer goes straight ahead. The other two is, one for the maximum rpm for engine and the other one for wich rpm the hydraulic should goes on. If you have the other one on lets say 1400rpm, even with the forward gear in, the hydraulic dosent do anything before you rise the rpm to over 1400rpm. So you should can stand still with engine even if gear forward or backward is on so long the rpm on engine is lower then you have put the potentiometer on. I had big problem with the moogvalve on the hydraulic pump, one of the electric spools in the burned up so I got an specialist to make a new one.