ive noticed no one has commentented or mentioned a wire overlay. depending on the particular car's brake system is wired, using long wire/wires,pretty much bypassing everything. more simply put just run your wires directly from brake switch, to bulb, eliminating current brake circut and using the one you just created. (not sure if bulbs get all 12v?if not then use resitors to achieve the right voltagez) getting too technical but yeah.if the sytem works fine off of the circut you just made,then you def have a problem in the wires you bypassed. if break/short cant be found, use your own circut and clean it up a bit. when all else fails?