Recently bought a pettibone crane got two weeks to move it. I got it running and got all the functions to work except I can’t get it to drive the most important one. Gotta load it on a lowboy. The other functions I made work by manually tieing off the pneumatic solenoids on the sides of the gear box the transfer case has 4 2 on the side and 1 by each output. Does anyone know what combination of what will engage the drive.