IT SOUND TO ME THAT WHEN YOU START RUNNING AT NIGHT ,THAT YOU ARE lOSING VOlTS THE FEIlD TRACKER CONTROllER. YOU MIGHT WANT TO CHECK TO MAKE SURE THAT IT IS CHARGING , IS YOUR VOlT METER IN CAB IN THE SECOND GREEN WHEN THE lIGHTS ARE ON. IS THAT THE ONlY THING THAT IS GOING WRONG , EVERYTHING ElSE WORKS FINE .