Well, I *finally* got the plow on the truck and tried to figure out the wiring. Actually, the wiring was pretty straight forward, but all the ends needed a lot of cleaning. Got it all hooked up. Nothing. Dang. went back and recleaned the terminals. Nothing. Only one switch activated the solenoid and only in one direction and no voltage out the other side. Clean the switch contacts again. No better. Swap on a solenoid from Heavy D. No better. Go to NAPA and buy an Optima Red Top and a new solenoid. OK, now we're getting somewhere. The solenoid clicks in every direction. But still no movement of the plow. And what's that? smoke from the motor every time I activate it. Doh! Check the oil level. It's low, so I top it off. Pull the motor off and sure enough, it's frozen tight. A little PB B'Laster and creative use of a screwdriver as a lever and I broke it free. Put it back on and voila, the motors turns. But still no movement of the plow blade. Nothing. It's not even trying. Hmmm...
Next thing to check is the magnetism of the valve solenoids. I'm sure the system could use a good flush too. But alas, it's now dark out and I might have to wait until morning (by when there is supposed to be a few inches on the ground). :-(
Probably the biggest storm we'll have for a few years and I won't be able to play with my plow. Of course, I seriously doubt that inoperative hydraulics will keep me from trying.