2005 Sea Breese LX RV is equipped with two Roof Mounted Dometic Air Conditioners. The duct fans have stopped working even though the Air Conditioner Compreser Motors operate. When fan switch is turned on there is a humin noise but fan does not operate. The ducts are in the ceiling. I can't find access to Fans.

Check with the manufacturer because you need to get to those fans. Sounds like they have seized up. Do not keep running the compressor until this is fixed.

Access to the motor is on the roof under the plastic shroud.