Rear Taillight Issues

[MMckenzie]

Hey y'all,
I have a 2013 Dodge Ram Tradesman that has been having electrical issues in the back since we bought it a year ago.

The right rear brake lights and turn signal mostly don't work- sometimes they cooperate.
The left rear brake lights work for the most part but the turn signal goes in and out.

I have tried replacing all light sockets and bulbs.
I have checked the fuses and they are fine.
I don't see a break in the wiring harness.
The top brake light on the cab works.
All the front lights work.

What do you guys think my issue is??

 

[chopperman1]

With all the randomness I would suspect a ground issue.

 

[Kayci]

Dealer told me my 3rd brake light is usually the culprit. Try checking that for water or corrosion. I'm still working on mine, so no report yet.