not sure what your wiring is like, but like said by scabber you could have a short or possibly a fuse went out or could need cleaning up if you have one. itll run just not charge the battery. but id start with a load test like leo said. any parts store should be able to do it. has your battery ever died? or does it start up with no problems? a starter will eat a battery pretty fast, so it may not be a battery...if you have a multimeter you can use it to check to see if something is grounding its self out. buy a nice one if you can dont go cheap on this tool.