[rheavn]

If the motor is turning, then the coupler may be stripped.  The fan is not going to come on until the lid raises a way.  If the motor coupler is stripped replace the motor and the lift arm---can't buy just the coupler. Two screws and pull down to see the coupler.

https://www.amazon.com/Fan-Tastic-Vent-K...si_vtp_0_t

https://www.amazon.com/Atwood-K6050-81-W...si_vtp_2_t

These were the parts that fixed mine.