There is a bank of hydraulic solenoids, 2 per slide - one for "In" and one for "Out". But if it's the pump motor, and it is intermittant, it may be a bad ground connection, or hot lead. Check that the connections are clean and tight at the motor's electric solenoid first, especially any ground wire, but I'm going to assume the motor casing and solenoid grounds itself by being bolted to the chassis. That solenoid should be mounted on the pump motor itself, and is what your mechanic is likely referring to. On my coach, as I recall, the pump, tank, and hydraulic solenoid manifold above it all are directly inboard of the entry step mechanism. The electric solenoid is very easy to access.
But use caution - that solenoid is fed by a 200 amp fuse on my coach, so I'd turn off at least the house main switch first. The juice may not be getting solidly through from the fuse because 1) the pump isn't tightly bolted to the chassis, 2) the + wire from the 200 amp fuse in the battery bay is loose or badly corroded causing high resistance, 3) one of the low amp connections (2 smaller wires) is loose, so juice from the switch isn't getting through to activate the solenoid, 4) the solenoid has gone bad internally and needs replacement, or 5) the motor itself is going belly up.
Just a place to start
-Joel
