I have a 2000 Sportsman 500-NON HO. The charging system has gone haywire! It will "overcharge" to the tune of 15.6 - 15.9 volts, the charging system will then shut down, the speedometer will quit working, the lights will go dim. Now, this will last until the voltage drops to 12.5 - 12.9 volts. The everything will work normally. Have put 3 rectifiers on to no avail. I know when it overcharges the relay will "open" which allows the battery to "discharge" until proper voltage is reached. I'm at a loss! What would cause this? Have been in the service end of the automotive business for almost 30 years and for the life of me, cannot figure this out. Everything points to the regulator/rectifier but that's not it! Any help would be greatly appreciated.    

KJUNMAN:
I have a 2000 Sportsman 500-NON HO. The charging system has gone haywire! It will "overcharge" to the tune of 15.6 - 15.9 volts, the charging system will then shut down, the speedometer will quit working, the lights will go dim. Now, this will last until the voltage drops to 12.5 - 12.9 volts. The everything will work normally. Have put 3 rectifiers on to no avail. I know when it overcharges the relay will "open" which allows the battery to "discharge" until proper voltage is reached. I'm at a loss! What would cause this? Have been in the service end of the automotive business for almost 30 years and for the life of me, cannot figure this out. Everything points to the regulator/rectifier but that's not it! Any help would be greatly appreciated.  

could it be a bad battery  

have you notice if your fan is kicking on or off during the times this happens or stops happening?  i'm sure it's shutting off is by design, charging your battery at a higher votl will cause it to burn up.. ever smell like rotten eggs? that's your battery burning up... however something else maybe causeing a short... heat related maybe? something to look at, start isolating all the things that use power, lights, hard wire your fan, etc.. just thoughts, hope one of them helps.  

bad battery will do it too  

there are recalls on the electrical system for your unit.

although if you didn 't get it done when the alotted time for the recall polaris may not honor it.

they have had serious problems with some of them catching fire in the electrical system.  

WoW i have a 99 doing same thing im  in the same business to. i also have a 2000 that holds at 14.5 no matter what i turn on or gois on ? i switched reg same thing on  99 ... 15.9 and the lights blow out just before shut down . I ran a wire from reg. red wire to batt it did not go over 14.5 and down to 12.5 still not as good as the 2000? So i orderd a wire with the breaker in it from polars hope that will do it .
Let me no what you found ?
Bill      

Cant find any recall on that prob?