**HELP** 04' wiring issue

So I have a 2004 Ext Cab TRD Tacoma. I had a similar issue last year, and had the help of DeadBeatSon to solve the issue. This time, it is the RIGHT rear tail light(last time was LEFT side, did some rewiring from trailer harness). Brake light works. Reverse light works. Blinker Works. When headlights are turned on, the back right tail light won't light up, but all other functions work. The right side license plate bulb is out as well. I have replaced all bulbs. I am at a loss here. I am somewhat handy and mechanically inclined, but not with electrical. Ideas? Troubleshooting? Should I just cut off all pieces to the dumbass U-Haul trailer wiring that the PO had installed?

Can anyone in Denver help a guy out? I can provide beers. I would like to get this fixed ASAP, as I am sure some cop will be pulling me over in the near future to inform me about the issue.

Thanks.

 

Like you I had a similar issue (left side) where connection point for the bed cap 3d brake light was spliced in. First thing I'd check is the wiring at the right side taillight..may be a pretty simple fix if just a bad connection. Beyond that might a bad relay or fuse or bad connection at other end of the wiring, but not sure how to troubleshoot that...

 

So I do have a topper, looked at the fuses for the wiring there (3rd brake light), and the are fine. I am just kind of baffled at how all the bulbs works, but the right rear tail light won't light up when the headlights are on. It has to be a simple fix. The right license plate light, and the tail light (when headlights are on) have to be connected somehow, b/c they are both out (replaced both with new bulbs)

 

I'd first get rid of the U-haul harness.

Our trucks require a 6, signal converter to a 4 signal output. I have changed many of the trailer light converter boxes/plugs. Most are junk. Even the Toyota OEM boxes for the first gen Tacoma's were just crap. The second gen converter boxes seem to be built a bit better.