Hi Fred, Welcome to the forum..
How about your front landing gear? Will they go up and down? The landing gear uses same hydraulic pump and what is called a trombetta relay. The relay reverses the power to the pump.
The relay will be close to the pump and two large black wires will run to the pump.
You can test the relay by removing the green and yellow,wires and touching those terminals one at a time with 12v. See if the relay activates in both directions.
Try this, if works we will go,to,step,2. Do you have a level up system?
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2016 Siverback 33IK, Towed 50K+ mile
2018 Ford F-350 Lariat 6.7L V8 Diesel 4WD Crew Cab
"If you don't know where you are going, any road will get you there."