DFI MDL fuse keeps blowing

There's a whole bunch of things on that circuit, and to make it really confusing, the engineers used pink wires in every part, but they split it up, then fused each part separately. This fuse protects circuit 539, as shown with my pink arrows. The only thing on that line is the ignition control module. The wire going to it could have a bare spot and be touching the engine or a metal bracket, but the ignition module itself is the best suspect. If you unplug that module, then a new fuse doesn't blow, replace the module. If the fuse still blows with the module unplugged, I'll describe how to use a trick to avoid having to keep replacing fuses while we diagnose this.

Dandy. That eliminates the expensive part.

Sorry for the long delay in responding. Just got plowed out today after a big winter storm.

A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A common 3057 brake light bulb works well because it has the type of terminals that are easy to clip to. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against anything plastic. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out. In this case, move the wire harness around for the ignition module.

These drawings are two I produced that show part of the description for this trick. The bulb will limit current to a safe one-amp so the wiring will still be protected.