the awning motor has a positive and a negative(ground) run to it, they reverse the power black becomes + and red is negative to run the motor to roll it up. You most likely have a short to ground on the black ground wire , when you go to retract it your sending 12 volts right to ground . check it for a grounded wire at the motor, mine you can disconnect it in the arm just before the drum. If the motor isn't grounded then check the wires going back to the switch , my guess is the wires going back to the switch .
Mark & Melissa
2015 Redwood RL38 , Kodiak disk brakes , 17.5" tires , 8K Morryde IS