The battery on the 300's is between the two firewalls near the passenger fender (under a plastic cover) right next to it are two relays, one for the fuel, which causes the exact problem that you are having. Sorry but don't know about the location of the 400's adn therefore if the rleays wer moved also, but the problem is so common that the relays are carried by the 800# service trucks. A call to the 800 or your local dealer should help. Because your vehicle isn't running the service truck should check it for free, I think, and charge you for the rleay..