Bulb failure light went on past Wednesday. Identified the right rear brake light as the issue. (All parking lights operate.) Swapped left and right brake light/parking light bulbs and failure of the right rear brake light remains the issue. I removed the right rear tailight, cleaned all the bulbs, cleaned the bus bar, cleaned all spade connectors and the ground point on the car frame. After reinstalling tailight with new bulbs in both the left and right brake light/parking light sockets, I measured voltage and have same voltage at both left and right tailights as reads at the battery. The bulb failure light remained off until I pumped the brakes a few times. Now both the left and right brake lights do not work, the 3rd brake light does work and the parking lights do work. Any opinions on what is wrong or to check next? Has the bulb sensor relay gone bad? (I have a chance for a run to a pick-n-pull tomorrow.)