2004 John Deer Buck Utility ATV 500, 500EX and 500EXT Service Manual, Page 172Get this manual
Unplug the temperature sender connectorsUsing multimeter, measure the voltage between RED BLACK and BLACK wiresThe obtained value should be between 12 and 14.5 Vdc No voltage: Check accessories fuse and wiring condition Voltage is good: Check outer accessoryApply parking brake, place transmission lever in NEUTRAL position and start engineSelect low beam position on multi-function switchUsing multimeter, measure the voltage between the following wiresRemove the steering coverUnplug the power outlet connectorsUsing multimeter, measure the voltage between RED BLACK and BLACK wiresThe obtained value should be between 12 and 14.5 VdcModels Buck Wires Green and Black Values 12 to 14.5 Vdc Install jumper wire end in connectorsReplace the fan if it does not work The obtained value should be between 12 and 14.5 VdcPlace the headlamp switch selector on high beam position or activate the dimmer switchMeasure the voltage between the following wiresModels Buck Wires Blue and Black Values to 10 Vdc