funny how these things pop up in groups. The same question was asked last week or early this one. The common repro harness cause of this is that the center horn contact in the light switch bulb is off center and hitting the switch plate. Slip some shrink tubing over it so the edge of the contact is insulated. There are a few others, follow the link http://69.61.21.195/forum/showthread.php?t=21719