The JCB 401M8903 is a genuine OEM alternator resistor, specifically designed for JCB agricultural and construction machinery. This 220 Ohm resistor is a critical electrical component for regulating the alternator's output, ensuring stable power generation and protecting the electrical system. It is compatible with a wide range of JCB equipment, including 3CX and 4CX backhoe loaders, various Loadall telehandlers (e.g., 531-70, 540-140), and Fastrac tractors (e.g., 3230, 8250). This authentic JCB part ensures optimal performance and reliability for your machinery's charging system.