I had the same problem earlier in the year. Most likely if happen when you step on your brake it either reverse or brakes. With mines none of the bulbs was blown but when I closely examin where the lights go in i noticed that even though I twisted in the light bulb it was still lose causing one side of the metal connector on light bulb casing not to touch the main housing. Pull out the metal connector on the casing a lil bit and hopefully this fixes your problem.