Compatible with Kawasaki KFX400 (2003-2006) 6-pin voltage regulator and charging system rectifier regulator, original factory code 21066-0042/21066-S004, ATV rectifier.

[Voltage Regulator/Rectifier Specifically for Kawasaki KFX400 Sport Quad] This high-performance 6-pin voltage regulator/rectifier was specifically designed for the Kawasaki KFX400 quad (models 2003–2006). It is functionally compatible with original part numbers 21066-0042 or 21066-S004. Manufactured to original electrical standards and 6-pin interface specifications, it ensures perfect compatibility with the quad's three-phase ignition system and battery. It provides a precise and reliable solution for resolving charging issues and replacing worn original parts. **【Highly Efficient Three-Phase Rectification and Precise Voltage Regulation】** High-efficiency rectification: The three-phase alternating current (AC) generated by the magneto is converted to direct current (DC) with minimal loss and a consistent output. This allows the battery to be charged and the power required by electronic fuel injection systems in high-revving four-stroke engines (such as those found in vehicles), high-performance headlights, and electronic devices. **Precise Voltage Regulation** Thanks to an improved control circuit, the system voltage is precisely stabilized within the optimal range of approximately 13.8 V to 14.5 V across the entire RPM range, even under high dynamic loads (e.g., during hard acceleration and inclines). This effectively prevents overcharging and deep discharging of the battery, thus protecting the engine control unit (ECU) and all electronic devices in the vehicle. **【Improved Heat Dissipation and Durability for Sport ATVs】** Optimal Heat Dissipation Design: The housing, constructed from highly thermally conductive die-cast aluminum with dense cooling fins, ensures optimal heat dissipation. Forced air cooling at high speeds and heat conduction through the frame quickly dissipates heat generated under heavy load. This guarantees continuous and stable operation even under extreme conditions such as deserts, racetracks, or off-road terrain. Off-Road Durability: Thanks to advanced sealing against water and dust, mud, impacts, and corrosion, the system is specifically designed for the harsh off-road conditions of the KFX400. Precise 6-Pin Interface: The unique 6-pin connector is fully compatible with the vehicle's original wiring harness, allowing for easy installation. Please ensure your vehicle's original rectifier has a 6-pin interface. [Resolving Persistent Charging Issues in Sport ATVs] Replacing this component can resolve the following problems: Severe battery discharge after intensive off-road use or sporty riding, preventing the vehicle from starting. Unusually rapid battery damage (overcharging is a common cause). A noticeable decrease in instrument brightness and flickering may occur when multiple electrical devices are used simultaneously due to voltage fluctuations. The vehicle's original rectifier may have failed prematurely due to overheating or vibration. [Easy Installation] The rectifier is typically mounted in a well-ventilated location at the front or side of the vehicle frame. Before installation, disconnect the negative battery terminal, disconnect the 6-pin connector from the old rectifier, remove the mounting screws, replace the old rectifier with the new component, and then tighten and reconnect it. Key Compatibility Information: Compatible Models and Years: Kawasaki KFX400 (2003, 2004, 2005, and 2006 models) Corresponding Original Part Number: 21066-0042 or 21066-S004 Interface Type: 6-pin connector (specific to this model) (Important Note: Before purchasing, please verify that the part number of your original rectifier matches one of the part numbers listed above, that the interface is indeed 6-pin, and that the appearance/pinout is fully compatible with this product. It is strongly recommended that you provide the seller with your vehicle identification number (VIN) or the exact year of manufacture for confirmation.) Scope of Delivery: