Electrical

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 brake light bulb works well. 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 a plastic door panel. 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.

What do you suspect is wrong with a ground wire? If it's corroded or broken off, that will cause a drop in current flow because it can't find a path to travel. Fuses blow from too much current flow. If the wire is rubbed through and touching bare metal, that will just provide an alternate path for current to get to ground, which the wire is already doing. Is there something else I'm not aware of?