As I trace wire it appears they are not on the same circuit but some of the wire are not able to be followed due to where they are routed. One person believes it is a ground problem. I must say electrical is not my forte. Worked with a friend who manually grounded the socket, and with the brake light switch in my hand I actuated the plunger, and the lights worked. As soon as I installed the switch on the top of the pedal and there was no one physically grounding the socket, there were no brake lights. there is a ground wire protruding from the harness but the sockets themselves are not three wire, they are two wire with an added wire to a mount screw to act as ground i believe.