my understanding. is that a spring pushes the awning out as it unwinds
the motor is used to Retract the awning which winds up the spring
so they all go out faster than they retract/wind-up
sounds like you have either a power problem, not enough voltage to the motor
or a binding problem
i would lube everything you can
and then i would check the wiring to the motor
a corroded or loose ground/negative wire would create a power problem
last choice .. replace motor, probably have to buy the complete assembly-arm section that contains the motor
lets hope you don't need to do that