The truck in question is an 05 F450 6.0 PSD. Before anyone gets the wrong idea, it's not me trying to disconnect the odometer. It's one of my company trucks, and my employees drive it (1 guy drives it about 95% of the time, unless he's off/vacation/etc.) But, one of my other employees had it for about a week. During that time he drove about 80mi for work (on 2 consecutive days at the start of the week.)

Here's the catch, he took it with a full tank, and when I got it back from him the tank was damn near empty. There was a bunch of mud, sand, and even still some water in the hitch and bed. I know he owns a 20-something foot boat, but at the moment he doesn't have anything that would even entertain the idea of towing it. The nearest lake he could've taken his boat is at least 100mi away, which would account for the fuel discrepancy and water/mud. I should mention that it has a locking gas cap that appears undisturbed.

So I'm thinking he may have disconnected the odometer to take the truck for personal use, or siphoned diesel out of it (though he doesn't have a diesel.) Is the odometer (and assumably speedo) run via the VSS or ABS system or something else? My searching suggests that it's based on a VSS in the rear diff, but I'm not sure that applies to an F450. Thoughts?

 

I have been told it can be done and it's simple as pulling a fuse.