A-RE240999-AI Relay; 40 AmpOne New Aftermarket Replacement 40 Amp SPDT Relay for John Deere Agricultural and Construction Equipment This Single Pole Double Throw (SPDT) relay is a 40 amp, 12 volt electrical switching component used throughout John Deere agricultural, construction, and skid steer equipment. It manages circuit switching for systems including lighting, ignition sequences, and accessory controls, routing one input signal to either of two output circuits.