OK, There seems to be alot of you doing this on here. WHAT YEAR AND MODLE do you have! This is a very important thing to know. Also a little bit of history abour the problem would be good. Did this just start all of a sudden, have you recently changed any bulbs, recently installed a trailer harness, do you have a trailer harness?
Get back to us and let us know some things and maybe we can help.