My break lights and backup lights were not working. The circuit boards on my 1990 wagon tail light assmblies were acting a little strange, with some of the lights being overly sensitive to tweaking the position of the bulbs. Since my tail light assemblies were getting old and the circuit boards were a little flaky, I replaced the assemblies. This however did not correct the break light and backup light problem. I finally took it in to the shop. They had to replace the shifter bushings and adjust the backup light switch that goes with the shifter. For the break lights, they replaced the bulb in the "third light" and now they wall ork fine, but that part was still a bit of a mystery. Anyway, it was $100, so could have been worse.

Were the lights working before you did your repair work? If so, then work back on the wiring circuit to see where the relationship could be. I am not good with electrical either. But I learned you can check to see if switches are getting power with a meter touching the powered wire, and the other to ground. Obviously there is no power to the bulbs. So I think you can work backward and see what is getting power, and what is not.