1998 Peterbilt 379 wiring issue

Sorry if this has been covered I’ve searched everywhere but can’t find anything

i have a 1998 Pete 379 when I turn my running lights on my right side turn signal lights up on dash and trailer and stays bright. It will flash if you kick on the flasher but the issue is if I don’t have my running lights on when using the right turn signal It flashes all lights on back of trailer and top row. I’ve tried multiple trailers all same issue, I was messing with the plug on back of sleeper today where light cord plugs in and found that when i use my right flasher it powers the black wire along with the green flasher wire, and also when I turn my running lights on the Black wire lights up also along with the running light prong. Only thing I can find online about this black wire is that it’s an auxiliary wire so no clue it’s purpose.

I’ve been messing with this issue since I got the truck in 2020 and can’t seem to locate an issue any help would be Greatly appreciated

 

** update **
After finding another 379 issue posted on an AG site the mention a flasher behind dash (speedometer panel) I pulled it down and found this clear round one inside has the flasher wires ran to bottom and a tiny black wire out of the top ran down further into the dash into (I think) a square black box looking thing. I’ve never seen this kind of flasher before so not sure how to proceed.
I’ve included a photo of the flasher I found