I have a 1996 F 350 Diesel with approximately 360,000 kilometers on it. If I drive the vehicle for 6 or 7 hours, the vehicle will power down, lose all power completely. If you try to start the vehicle, the glow plugs do not come on. If you leave the vehicle to cool down for 20 minutes or so, the glow plugs will light up and the vehicle will restart. Sometimes, if you feel that the vehicle is about to power down when it is in 5 gear, you can gear down to 4th, and the vehicle will keep running. However, it is only a matter of time before you continue to drive, that it will over heat and completely shut down. I have taken the vehicle to a number of Ford Dealership's who cannot find any problem. One dealer did find that there was quite a bit of corrosion from the main fuse box, and cleaned up this area. However, this did not solve the problem.

Any thoughts?