Jim Becker wrote:That looks like a Murphy gauge, a temperature gauge with an electrical contact that closes when the temperature goes past a set limit. The box is probably a relay that connects the gauge to the ignition system to cut off the engine if it overheats. You don't usually see them on a tractor. They are usually on power units that operate unattended.
It is connected to a temp gauge. for the info Jim Becker, I learned something new.