2004 John Deer Buck Utility ATV 500, 500EX and 500EXT Service Manual, Page 161Get this manual
and nutFirst connect RED (+) cable to battery then connect the BLACK (-) cableEnsure to slide protector over nut to hide metallic partsTest starter operation When dealing with ignition problems, the following items should be checked in this orderAfter one item has been checked and it is found not to be the problem, continue with the next item: 1MPEM (Multi-Purpose Electronic Module) fuses condition2Spark occurrence 3Battery condition 4Ignition switch 5Trigger coil 6Ignition coil 7MPEM
In dealing with intermittent problems there is no easy diagnosisFor example, problems that occur only at normal engine operating temperature have to be tested under similar conditionsIn most cases of temperature andor vibration failure, only parts replacement might solve the problem as most of these failures return to normal when engine is not running