If its still running then you might be lucky that the pump is not damaged, the big mistake dodge made was to not put a shut off safety if the lift pump should fail, diesel pumps run at huge pressure so heat and friction is helped by pumping fuel to the pump so it doesnt have to suck fuel from the tank, whats not used is curculated thru pump and back to the tank. So the fuel does lube and cool the pump, also cools the curcuit board mounted inside pump that when overheated will fry the transistors inside, there are some youtube videos of people fixing them. Could you have a bad relay if there is one?