Ford E-450 (1997 - 2008) - fuse box diagram - Auto Genius Jul 25, 2018The power distribution box is located in the engine compartment. The power distribution box contains high-current fuses that protect your vehicle’s main electrical systems from overloads. Ford-E-450 – fuse box diagram – power distribution box How to Install a Brake Controller on Chevrolet / GMC 1999 A: If the vehicle is already set-up with a flat 4-pole trailer connector, then plug it into the 4-pole on the back of the 6- or 7-way adapter that comes with the installation kit. The white wire (ground) coming out of the back of the adapter needs to be attached to a substantial grounding point on the frame. After mounting the new 7-way or 6-way connector, installation would be complete.