Donald, what motorhome year, make, and model do you have? What chassis is it on? A lot of the damper doors are controlled by vaccum. Diesel pushers have their own little vaccum pump up front somewhere that is 12 volt powered and a line off it goes to the damper door controller.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7