Recently my bulb failure light was active which alerted me to the third brake light in my spoiler. I replaced all six bulbs, but the lights still won't work. I've used a voltage tester and found no power at its lead. The lower left and right brake lights do work. I've noticed next to the left brake light assembly a light control box part number 9128814 that regulates 4x tailights and 3x brake lights. Since this little box runs retail $128.00 US I want to be sure I have covered all diagnotics before purchase. Any help would be appreciated !! My Volvo dealer has never seen this control go bad.

It could be the Brake Light Switch that is out. I replaced all my bulbs and checked fuses and still nothing, pretty frustrating...then I found something here about replacing the Brake Light Switch. After replacing that, everything worked fine. Check back through the past six months on this forum and Volvospeed, you'll find how to replace it. I replaced mine, the part was only about $30 but I honestly do not remember exactly how. Goodluck