If they are Power Gear the key mus be on but the engine should be running to ensure good operating voltage. Tiffin requires the key to be on for the driver side slides to operate regardless as to brand of slide out drives.
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