THE WARNING HORN ON MY '90 60VRO JOHNSON COMES ON IN A CONSTANT BUZZ WHEN THE KEY IS TURNED TO THE "ON" POSITION AND WHEN THE ENGINE IS RUNNING. WHEN I PULLED THE BOAT OUT OF STORAGE AND RAN IT TO MY DOCK LAST WEEK, I DIDN'T HAVE ANY PROBLEMS. I WENT TO TAKE IT OUT THE NEXT DAY AND THE WARNING HORN CAME OUT AS SOON AS I TURNED THE KEY. THE OIL TANK IS FULL. ANY SUGGESTIONS?