As Gary said plus under kitchen sink
or in linen closet or on your frame rails.
Check your 12v fuse panel for loose wiring at screw connections both + and - leads.
When you find the controllers unplug wiring connectors, pull connector plug and check wires in plug and clean with a contact spray especially if on frame rails box may not be tightly sealed.
Motors need to work with a good 12v's. May want to check negative battery cables to chassis frame.
Newmar slide spec with trouble section, other links for slide lock operation in QT's 1 & 2.