I would check the voltage to the motor. If it is low then work your way backwards to find where it drops off.
I had a similar problem with my awning having a very hard time retracting and found low voltage to the motor. The factory wiring was run from the control, under the floor behind the pass seat, back to the fridge area. Up thru that area to the area behind the cabinets over the pass side windows, forward to the wall behind the pass seat window. Down that wall and out to the awning in the small pass seat wall cabinet. Some of this wiring was too small a gage for the length.
I rewired, from the control, to the pass wheel well. Up thru the floor into the small pass seat wall cabinet, reducing the wire length by about 30 to 35 feet. This cured the problem.
2007 Limited SE 40fdts
Las Vegas, NV