[Harleydodge]

Lights "flickering" would be fairly normal if you tried to level without being hooked to shore power and batteries were less than fully charged.
Hooking up to the truck gave your unit access to the trucks battery as well, which would have helped the situation.

I know on our rig (with auto-level function) there is no actual fuse, but there is a 12v "circuit breaker" located behind the batteries in the battery compartment.
I tripped it once, but that's another story....
That being said, once it is tripped, you would have needed to reset it manually before any hydraulics would work again.

What you describe sounds more like a low battery situation, rather than a blown fuse.