How does anti-jamming fuel cut-off work? First, the core mechanism of fuel cut-off lies in the relay. A relay is essentially an electrically controlled switch. During installation, the relay is connected to the vehicle’s fuel control line. The two green control wires are connected to both ends of the fuel line, forming a controllable circuit. This allows the device to control whether the fuel circuit is open or closed through the relay. Anti-jamming fuel cut-off is not designed for signal blind