If it’s under factory warranty, Carmax will sub it out to the dealer. They are not stupid. Or at least the one by me is not. Why would they waste their time working on something that is covered by factory warranty? You should be asking them that. You can also take it there yourself if they won’t. Any dodge dealer will work on it. What I didn’t read in this post and you have not made clear, is have you tried the outlet with the engine running? Some outlets are only powered when the engine is running.