This 70-amp relay controls the electrical load for engine-mounted systems on the host tractor. It switches high-current circuits such as the starter solenoid, fuel shutoff, or glow-plug supply, isolating the ignition switch from the full current draw. A relay that fails in the open position prevents the engine from cranking; a shorted relay can leave a circuit permanently energized, draining the battery or causing unintended operation. This component is manufactured by AGCO to match the original contact gap and coil resistance, ensuring the switching threshold and hold current are identical to the factory specification. On replacement, verify that the relay base is clean and that the retaining clip engages fully to prevent vibration-induced contact chatter.