So, after the slide comes in two inches and stops, does re-engaging the switch make it move more? If so, it may be operating normally (the motor shuts off when the current its pulling exceeds a set amount) and recycling the switch allows the motor to start from scratch again. If it doesn't move any more at all, you maybe have something binding, or you have too much weight in the storage bays on the slide.
Will & Di
2004 Southwind 32VS
Workhorse/8.1
Ford C-Max/Blue Ox
"We have met the enemy, and he is us" Pogo