05 Sportsman Electrical Problem???

[Wellcraft270]

This one seems to have everyone stumped. 05 Polaris 500 Sportsman. Noticed in the spring the digital tach showing low numbers off and on - would run around 6000 which seemed normal but would then drop to around 3000 on the tach without change in engine speed. Over time this got worse. Now if I run wide open, the tach will actually start counting down backwards, once it hits 0, the battery light will start to flash. The headlights will flicker and it will lose power going from around 55 mph dropping down to around 40 and will hold there. Starts fine, seem to run fine at lower speeds. Happened off and on a few times in the spring. Very consistent now. Assumed a bad battery - replaced and exactly same symptoms. Checked connections I could get to. Revved it up in neutral in the shop and could see some flicker in the headlights so seems to be RPM related. Thoughts?

[Wellcraft270]

Gave up looking for it myself. Took it to the dealer. Problem is supposedly in what they call the Sure Power Box (assume it is the main brain which think was already replaced once on warranty at the same time they were replacing both clutches after the secondary came apart). 2nd Polaris '05 in the group I ride with that the clutches fell apart on. Been in the shop for a week, missed two weekends of riding. Dealer now says they don't even know when Polaris will ship the part. Borrowing a Bombardier to ride. Already switched to SkiDoo for snowmobiles and about to give up on Polaris entirely at this point.