Available as a conversion kit, the Electric Hopper-Door Opener eliminates having to hand-crank the grain trailer/ wagon bottom unloading hopper door(s). Since activation is via wireless remote, one can open/close the door from a safe, dust-free distance. The device, which slips over the existing crank shaft, includes housing-protected high- or low-torque gear motor (depending on make/model), braking mechanism, mounting hardware and wiring, hand-held remote.