Yamaha 4SH-86510-00-00 Fan Motor Control Unit

The Yamaha 4SH-86510-00-00 Fan Motor Control Unit is a sealed electronic module that regulates the radiator fan under engine-temperature conditions in Yamaha motorcycle cooling and electrical control systems. It accepts a temperature-based input signal and delivers fan-motor switching control to activate or cease the radiator fan, helping to prevent overheating and maintain engine efficiency. This OEM-compatible control unit is designed for plug-in or bolt-on mounting with an OEM wiring interface, and is commonly used in Yamaha motorcycles (model-specific fitment) and small-engine assemblies during maintenance, repair, or retrofit to restore cooling functionality. Common replacement references include Yamaha 3Y1-86510-00-00, 2A6-86510-00-00, and 1T3-86510-00-00.