varry odd trans problem please help
 

i'm new with the hyundais i mostly work on old muscle cars but a friend of mine just had her a/c fixed the blower motor was replaced and after it was replaced her transmission started sticking between what i believe is 2nd and 3rd gear(between 30-45mph),dose anyone have any clue what was messed up? its a 2000 accent GL,if some one can help please do so,i am confused considering the a/c and trans have nothing to do with each other,all opinions are appreciated