Polarity Converter for H4 Headlights Function and compatibility Polarity converter reverses polarity (negative to positive and positive to negative) to support all kinds of cars. Suitable as a polarity converter for H4 harness adapters and as a replacement for polarity converter kits and polarity converter boxes. Available for use as an H4 polarity converter kit or an H4 polarity converter box. Ballast interference suppression Includes a decoder with a efficiency interference absorption circuit. Reduces ballast interference pulses to less than 1/10 of the original level. Eliminates interference from the ballast to the driving computer. Problems it solves Improves performance of most modified headlights where the light is not bright enough. Addresses issues where headlights cannot be dimmed or the dimming switch becomes warm. Practical use scenarios Scenario 1: Upgrading to LED or other modified headlight systems in vehicles where the original polarity wiring would cause issues, ensuring proper operation. Scenario 2: Replacing a faulty polarity converter in an H4 headlight setup to restore brightness and reliable dimming. Scenario 3: Installing in vehicles with ballast driven headlamps to minimize electrical interference with the vehicle's driving computer. Performance emphasis Universal applicability across car makes and models. Focus on reliable polarity reversal, compatibility with H4 systems, and mitigation of electrical interference for safer, steadier headlight operation.