On way to South Dakota last week with my 2015 V-Series 3805 I realized my left tail light was not working and right tail light had "missing" LED's. Fortunately, I had brake and turn lights and didn't do any night driving. Upon investigation found the tail lights to be Command brand model 003-6018 and mounted through the bottom frame rail beneath the ramp door - but the back of the rail is open to weather and road splash. These lights have "holes" in the housing that lets moisture in causing failure of the LED circuit board. Bad application of these lights by Dutchmen.
In checking Command's website, they offer a model 003-6019 which is a direct replacement, but has a completely sealed light housing. I have replaced my tail lights with the 003-6019 and all is well again!