Have RV Questions? Ask an RV Mechanic Online.
Hi my name is Robert...
I would go to that connection point and check for voltage with a meter, you should have over 11 volts, what you can do next is get a charged drill battery and jump the fan direct with some small jumper wires and see if the fan stays spinning, if the fan does the same thing bad motor as you are jumping direct. IF you have the same problem then there could be a circuit board involved, normally that would be part of the monitor panel system. Have to check the voltage to starts and see what it is, if the voltage in the trailer was low then the fan could come on but as the low voltage tries to run a motor it could shut down and the lights still may be on.... Hope this gives you some direction.... Let me know if you have more questions or concerns....... Robert