JCB 70421600 Steering Mode Relay Box Assembly

The JCB 704/21600 steering mode relay box integrates electromagnetic relays into a centralized printed circuit board module. It manages low-current signal switching for high-current steering circuits and provides wiring overload protection across JCB construction equipment. The unit operates at 12 volts with a 20-amp rating through a 4-pin connector interface. Designed as a direct OEM replacement for JCB part number 704/21600, it fits backhoe loader models 3CX and 4CX as well as telehandler models including 531-70, 540-140, and 550-140. The assembly mounts within the machine electrical architecture to control steer mode selection logic.