I have Pontiac 2002 Montana Van, The lites on the right side of car all flicker when the right flasher is turned on and brakes are applied only at night. Also the flasher lites in the dash are lightly iluminated at all times. When the left blinker is turned on everything on the left side works properly. When I first got this van I inatalled a trailer hitch attachment assy. With all lites working properly after the instillation. This problem just started within the past six months. (Note) head lites work fine.