Is there a fuse on a 2008 F250 Powerstroke for the trailer Is there a fuse on a 2008 F250 Powerstroke for the trailer lights? All I located in the manual was a location for a relay under the hood in that fuse box. I dont want to replace the relay until I know that there isn't another fuse to check. Thanks! Interior Fuse Box Location: 2008-2016 Ford F-350 Super Duty Some Fords have multiple interior fuse boxes including in the trunk - the video above will show you where the interior fuse box of your 2008 F-350 Super Duty is located. If your F-350 Super Duty has many options like a sunroof, navigation, heated seats, etc, the more fuses it has.