Sounds like you are describing a 12V circuit breaker. There are several types, and some have a "reset" button on the top between the terminals, or on the side (a small button that protrudes from the device.
They are available in most auto parts stores. Just match the current rating (20A, 30A, 40A, 50A) that should be on the device.
2013 Rockwood 8289WS
Mods: Central Vac, PI EMS-HW50C, 2025RV, (2) SCS225 Trojans, PD9260, Awning Remotes & LED Lights, Eliminators, External Water Filter,, Intellijacks
2008 RAM 3500 Cab&Chassis Hauler Bed, B&W Companion Hitch
All My Modifications are at this link: