Rear tailight assembly problems need help

[Dimond9035]

Okay guys here is what is going on when I turn my lights on my right rear taillight works fine when I hit the breaks the running lights and turn signal/break light goes out and my reverse light comes on this is only happing on the driver side, when I turn the turn signal on nothing happens in the back the mirror and front blink very fast so I assumed one of the duel filiments burnt out I replaced the bulb and still does the same thing, does anyone have any idea what I should check next???

 

[Dimond9035]

I followed the wires down below the truck and found a few frame grounds cleaned them up real good and my break light issue is gone but the turn signal still does not work, any idea guys???

 

[ABNLT]

I had a similar problem on my Yukon. Check for continuity across the plug in the wiring harness just below the taillight. The plug is behind the bumper cover. I found that one of the connections wasn't making contact across the plug, so I just bypassed the plug with a direct connection for that wire. Just be aware that if this is the problem and you want to change taillights in the future it will be more involved than just unplugging the old light and plugging the new one in, you'll have to redo any wiring repairs you made.