My 04 Scrambler 500 rolled back down my driveway into a set of trees. I guess my brake wasn't tight enough, lucky enough nobody was hurt. Although the 4wheeler wedged into a tree. The key start hasn't worked in a couple months but pull start every time on first or second pull. When I turned the key, no lights anywhere, no headlights.....and of course I wasn't able to pull start. So is there a fuse that might have broke? I pulled middle plastic and wiggled key power supply to no avail. I hooked up to battery charger, but still no avail. Any ideas on this thing before I set a match to it? Thanks in advance!

 

There is a fusible link off the battery but you can test to see if it's ok. Also has the ecm module that has the circuit breakers and power for the dash,lights,fan,etc that can cause problems also.Items #22 and 23.Polaris ATV Parts 2004 A04BG50AA SCRAMBLER 500 4X4 ELECTRICAL-TAILLIGHT Diagram Here's a cheap service manual that can help also.http://polaris-atv.brssm.com/2004-Po...ce-Manual.html

 

 

You can test the fan thermistor on the head by checking resistance readings when cold and when warm. Resistance should drop as the sensor warms up. Cup of hot water can tell you if it's working ok or not. Plus yes I've had fans kick on when sensors checked out ok because the ecm shorted out. Not too much to check except there will be power coming into the ecm,but no power out,you might as well say it's failed.You don't give what model you have but the cheap service manual has a little info on ecms. Might be worth the 5 bucks to make sure you can eliminate other problems and narrow it down to the ecm module. Polaris ATV Service Manuals PDF Download