Hi cmal. Blind Internet diagnosis is not possible for an issue like this. Your best course of action would be to get a second opinion from another Dealership or an independent shop you trust.2015 fusion had driver door and fender replaced, now heat, radio and display screen not working properly. dealership claims the door harness was wrong and caused a short, they want 5,000$ to fix. don't believe them hoping for a second opinion
Also, you are not providing much information. Who replaced the driver door and fender? You? The same Dealership that told you the "door harness was wrong"? When did the other problems begin? Right after the door and fender were replaced? If the Dealer installed the "wrong door harness, why aren't they making it right, etc.?
Either way this can not be blind diagnosed.
Let us know how you make out and good luck.