Reverse lights trouble

[Camy13588]

 

So I bought a 5.3 2015 1500 SLT sierra and on my test drive the warning for passenger side signal light failure came up on the dash, figured it was just the bulb, turns out there was no power at all going to the passenger side meaning no stop/turn/tail or reverse light. So when I got it home I took the passenger side Tailight apart to find the bottom light socket completely cut out out of the harness, no big deal got the p/n (22869171) and ordered a new harness. I installed it today. Well its better then what it was I now have blinkers (still hyper flashing) tail lights and brake lights. But when I put the bottom bulb in and turned the lights on the bulb burnt out after a few seconds, tried another bulb and same thing. I still also have no reverse lights on either side. So to summarize, the bottom bulb keeps burning out on passenger side and I have no reverse lights on either side. I know there’s the junction block above the spare tire (p/n 23208491) that is known to fail in harsh climates which I do live in eastern canada where they pound the salt to the roads worse then McDonald’s fries. I’m worried about spending the 200$ on the junction block and it not fixing my problem. Anyone have any other ideas of what it could be? 

[PFTX_5.3]

Id check the connections in the wiring harness between the jbox and taillights first