My brake lights are not working, running lights work except the right top one & 3rd brake light does work.

Exactly what I did this weekend. Then I took a step back & realized I didn't check individually the lights, turns out the lights I bought before although same # didn't work & the other light that the running light worked only, the duel filiment was half dead. Felt pretty stupid, replaced all lights & everything works, lol.
Now to try & fix the main issue alot of ppl have I've read. Service 4wd! Switch works fine, TCCM gets no signal but far as I've read it could also be the transfer case shift control so guess I'll replace that before the TCCM, sucks not to be able to get a straight answer what's wrong, even dude at shop couldn't figure out which one, I can do them both myself so I'll at least save some $ that way.
Any info on that problem would be greatly appreciated of course!

Thanks for searching around before I post the question on a new feed, I'll be foing it tonight. Really liking this this site & will be recommending this site to anyone I know with questions about they're car or trucks.