These back lights are gonna drive me crazy. Discovered a loose red wire was the cause of inoperable left tail lights, a jiggle fixed it. But now the brake light on that side won't come on. And somehow, while fiddling back there, I've rendered the backup lights inoperable on both sides. Fuses and bulbs are OK. Any ideas before unavoidable inspection tomorrow (Monday)? Why would both backup lights stop working at once? And does anyone know which color wire feeds the left brake light?

((Michael, thanks for your guidance on swapping circuit boards. But when I hooked up the old one (with the wire harness and the ground wire, but not installing the assembly on the car), no lights worked at all so I guess it's no good.))

Thanks
Cal