Weather Pro, Power Gear slides and AccuSlide slides all have one thing in common.. The type of controller.
There are no LIMIT switches,, instead the controller monitors motor current and if it climbs above a pre-set,, Shuts off, it's that simple
The motor is seeing too much load when extending.... Why can this be?
Too much tension on the counter spring would be my guess.
IF you know how to apply/remove tension Unwind the spring a turn or two
If you do not.. Find someone who does.. There is a lot of tension on that spring and a mistake can put you in hospital or worse.
Home is where I park it!