i have an 05 trail boss 330 that i am having a battery issue with. my battery went dead so i replaced it with a nice fresh charged battery, fired right up as it should. let it sit overnight and had a no start i checked the battery and it had low voltage. recharge battery and with full charge nothing. check battery has charge but no start disconnect the ecm and replug fires right up. next day battery is dead. took off ground and put volt meter between ground wire and ground on battery. showing 11.6 volts with everything off and key removed, if i disconnect the ecm i no longer have a draw. i started unplugging connections looking for where the issue was but ran out of time before i found anything. hoping someone here can point me to what might be causing the draw with everything off. i assuem it could be inside the ecm itself but would ratehr test before throwing parts at it to know for sure.

thanks for any help

 

If you're not riding I would take the wires off from the battery. But when you do ride, just put the wires back on. I have no idea how to fix this but I do have this information. They may be shortening out.

 

They had a big ecm recall on this problem on the 2005 models. Even though your 330 wasn't on it,I replaced several 330 Ecm modules. It controls the charging along with the fan operation.You can check while idling that the battery is receiving 14 volts from the ecm module. If not charging it may be the problem.Item #18. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse Plus you can't overlook a battery being bad straight out of the box either.I've had plenty of those too.

 

U may have just left the jey or stary switch on overnight

 

just to close this out and help any one else searching. I replaced the ECM and that seems to have solved my issue with the battery draining down. thanks for the help

 

Should have been under the free recall,but wasn't! I really believe Polaris knew all the ecms were defective! Main thing it's fixed and hopefully no more issues.

 

Some riders use the kill switch on the handle bar to kill the engine, then turn off the ignition switch, A few days later they go to ride and the battery is dead. This was a recurring problem on my stepsons 4 wheeler and he thought he just needed to have a battery maintainer hooked up to it. I finally got his ok to look at it.
I put jumper cables onto the battery turned the ignition switch put the kill switch into the middle position hit start button and it started, and let it run. Put a volt meter on the battery (without the jumper cables) and it showed a charge of a bit over 14volts dc. Ok Ok the unit is charging there has to be a short somewhere?
So I said ok we try to find a short, turned the ignition key to off and BINGO the thing kept running, pulled the key and it still ran! I had to use the kill switch to turn it off. I removed positive battery cable and removed the ignition switch and found one of the spring loaded contact was stuck with some plastic flash hanging it up. I rimmed off the flash with a utility knife made sure it was free, cleaned the contact bands inside the switch , sprayed with some WD 40 reassembled, PROBLEM SOLVED.

 

Yes switches were another weak link on a lot of Polaris models, 325/330 included. I've had a couple just like that that would keep running with the key out. Techs didn't have the time to check every switch out,they chunk em and replace them cheap as they were. Plus we kept switches in stock for several trouble some year models. Glad you were able to find the problem on yours.