Tail light acting weird

well i just got the jeep back today from getting a new front end and t-case and while he was at it my mechanic swapped the busted tail light from my 94 out for the good one on my 95, but instead of just using the shell he used the whole wiring. now the tail light doesn't work, but my brake light does and the marker will only blink when it's in park. when i'm driving it will just stay on. i think this is because my 95 had power windows and locks, but that shouldn't make a difference. maybe i can go back tomorrow and get the old one back but in case i can't what could cause this? TIA

Thought they were the same. I would check the grounds and bulbs/sockets.

this is what i thought too. i'm hoping i can get the original wiring back because it worked perfectly fine