hi , ive had this 1994 Regal buick custom, the problem is that my rear brake lights arent functioning when i step on the pedal, the only brake lights that turn on are the interior back window lights but not the ext. backlights, ive checked the fuses and made sure their all ok, ive checked the bulbs, they are in working order, the only time that all the lights turn on are as if i turn on both the hazard and parking lights. any suggestions or comments on what might be wrong?