What is that little silver block?

[John Young]

that is on the positive lead wire going from the battery to the slide motor?

It is a bit rusty on one screw and must not be making solid contact.. hence the slide did not work today..

but, I jumped across the two screws, and it worked..

when I would wiggle the wires, it would give a shorting sound from those wire connections and then not work..

what is it and is it needed??