LGF be sure your getting the signal from the controller energizing the S1 cartridge valve which controls lowering of the plow.
I will be the small socket on top left corner of your truck side connector with the raised part of the connector up, should show battery voltage when testing.
If you have current then check to see if the coil is activated by seeing if you can stick a screwdriver on it while its activated.
If so check the valve and see if it's stuck.
With the other one if you have "no" fuctions I would first check the multi pin connector, see if its making a good connection.
Again see if you have current at the coils on the power unit.
If so I would be checking for a clogged filter.
As it would be in the pump section if all valves are operating and and you have no plow funtions at all.
Hope this helps you out.
John- I tried to help out Mike 97 SS- he's having problems with his blade raising when it has any more weight on it other than the blade itself. I downloaded the Mechanics giude and was going to post some of the info here- but I'm having problems with my Adobe right now. Mind if he gives you a call? He's done everything but change the solenoids or test them and he hasn't checked the poppet valve or crossover valve. I don't want to refer him directly to you- but if it's ok, just PM me or him- I have his email address if he's not online.
So glad I could help plus I got to come inside and warm up while I was talking to you, I have water now too.
Bill I have a "phone date" tomorrow with the other Mike, hope we can get his plow up and running too.