Need a little advice on where to go next with my search for reason of blown fuse. My brake lights on my truck went out. I checked the fuse in the cab and that fuse was good but the one in the engine compartment was blown. I change it and the brake lights started working again. Drove for about 2 minutes and no workie again. I checked all the wiring that was visable and couldn't find any loose or exposed wires that might be grounding. Changed fuse and same thing happened again. Anybody have any idea where to check next before I have to go to a shop. I haven't installed anything new or used the trailer light connection so I'm at a loss. Thanks in advance for any help.