The members is very good source, I just replaced the motor. the techs at Lippert were very good also, It sounds like the  nylon ring gear is stripped, soon as I removed the old motor you could turn the little gear by hand,  I might have let it go too long.  There are about 6 sources for the motor from $290.00 plus fgt. to about $170.00 free fgt.   The cheaper ones will have to be drilled out to 1/4" To fit properly.It took about an hour.