This is where a little knowledge & a cheap tool would be pretty near priceless. Get a cheap volt-ohm meter, aka VOM. Harbor Fright has 'adequate' ones for under $10. Learn to use the 'DC Volts' setting.
Check the power supply starting at the motor, and working back toward the source (house battery?). You can also use the continuity ('tone') setting to check that the switch is functioning if the motor isn't getting power. You can also use the tone to actually check the fuses. They can be blown without showing it sometimes.
Really, every thrifty RV'er ought to have one in his tool box. It + knowing how to use those two functions can save you $$$ thousands over its life.
Jim, "Mo' coffee!"
