OK, this one is weird. I'm guessing it's a short or something where all three positive leads are shorting with eachother, but, not sure...
If I use ANY of the three lights INDEPENDANTLY, everything works fine. Blinker only, OK. Brake only, OK. Reverse only, OK. There MAY be a little "bleedover" to another light, but not much.
As soon as there is ANY combination (brake + blinker, brake + reverse, reverse + blinker, or all three), then all three lights have current to them, and sometimes the brake/reverse lights blink with the blinker, etc...
Ummmm, how do I troubleshoot this? Is it a short? Fusepanel?