Honda XL500S Headlight Voltage Regulator


My 1980 XL500S taught me right away, you want to kick start it wearing boots.  I used to tell friends that wanted to give it a go, if you can start it, ride it all you want.

If the battery is not viable or missing, lighting Voltage will skyrocket. Bulbs blow, especially the expensive headlight bulb. Once the bike can blow one bulb, the rest will blow in rapid succession.

For an unknown reason some Hondas begin producing excess headlight Voltage with age. The problem is in the stator.  Its a mystery exactly why, even after unwinding several stators. This can happen on bikes that have been OK, and some bikes were shipped this way. Even with a viable battery and all bulbs intact, headlight Voltage is too high.

After years of working with these problems, Jon designed a special Voltage regulator to control the excess Volts to help prevent headlight and bulb failures. The device is ruggedized, waterproof, and plugs in. Installation is simple. Wires and connectors are color matched. The regulator plugs in without modifications to your Honda’s wiring harness.  It fits inside the headlight bucket on some models, and just outide it on the versions with the compact headlight housing.

Thanks to Eagle-Eyed customer Wayne for catching an error in the instructions about the ground wire in July of 2014.  Made the correction!

The Pardue Brothers have designed and tested this device to destruction, and it has earned our seal of approval. We hope it rates as a quality item that Soichiro Honda would have approved of.  The device plugs in, and is simple to install even for those with no wiring experience.

SKU: 6VACRXL500S Categories: , , , Tags: , ,


This 6 Volt AC headlight Voltage regulator is the result of owning an XL500S.  Some of these 6 Volt bikes have a nasty habit of blowing the headlight bulb filaments if the battery is electrically disconnected, missing, or for any reason is unable to accept proper charge.  Some develop excessive headlight Voltage with age, even with a great battery.  The regulator has no effect at low engine speed, allowing the headlight to remain as bright as possible.  Once engine speed increases headlight Voltage above 6.8 Volts the regulator smoothly kicks in and burns off just the excess Voltage, leaving the headlight fully bright but undamaged.


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