1971 XR7, reverse lights do not work. I replaced all bulbs with new ones. All tail lights, light up. When you hit the brakes, the rear right, furthest right light goes out completely. Turn the left signal on out of the 3 lights going left to right 1,2,3. 2&3 flash but one does not. On the right when you turn on the signal going from left to right1,2,3 1 and the flash and 2 does not. Any ideas?