I removed the dealer from license plate. Once I removed it, I saw the outlet cable just hanging there. I don't have a check engine light on. If it's worth anything it was a fleet car. Does anybody have any idea what it might be? It's a 2014 v6 manual mustang. Any help would be helpful!

 

Maybe an engine block heater?

 

^ That was my thought too. If that car has spent much time up north, I'd bet good money that's what it is. You can still find a lot of cars up here with those cords hanging out the grill.

 

Looks like the cord that is behind the grill on my F 150, coming out of Canada I know all the F 150's have a block heater. Fleet and rental Mustangs do also.
Gravydog, my Mustang sleeps much better with his Battery Blanky.

 

That's a block heater. I have the plug and leads for my canuckistang in my basement, in a bag. Came standard with the car.