Recently got a 2008 polaris sportsmen 500. when i bought i the guy said the battery needed replaced. well replaced the battery and the thing will still die every few days. also noticed the tachometer on the screen and the hours arent shown anymore either. Not exactly were to start looking is the first 4 wheeler ive owned. any of yins have similiar issues and wat was the problem?

 

Check while it's running that you are charging 14 to 14.5 volts back to the battery. If it's not charging,just showing battery voltage,the ecm module is usually the culprit.It mainly controls the charging and fan operation.The low voltage may be the cause of the display problem also. Item #1. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

Checked the voltage with quad idling and it barely started with the ignition ussually have to pull start it once the battery dies. was getting 9.8 volts across the battery terminals at idle.

 

Not charging will drag a new battery down.Check the tests on the stator from the pdf link I posted (to eliminate it as the source of the problem also) plus other checks that you can do to narrow it down to the ecm for sure before you order a new ecm module. Sorry didn't give you a link earlier http://gh-ftp.com/ORV%20Manuals/Polaris/Sportsman/2008/
If this is for the efi model only,here's a 5 buck pdf manual for the carb model with the ecm module.
http://polaris-atv.brssm.com/2008-Po...ce-Manual.html