This 1998 Ford Crown Victoria came in with the complaint that the #2 fuse in the underhood fuse box will blow while going down the road. The customer stated that he could tell when it happens because the air bag light will come on and the charge indicator gauge will start dropping. The test light is pointing to the #2 fuse in the underhood fuse box.
I did a lot of searching to find the short but it turned out to be in a pretty easy location. One of the wiring harnesses was rubbing on the wiper motor mounting bracket at the center of the picture below.
A close up picture of the harness with damage.
You can see below that the yellow wire has an arc mark on it.
A better picture of the damaged yellow wire. I wiped some silicone sealer on the damaged wire. Taped the harness and put it back in the loom.
Then I split a piece of rubber hose lengthways and slide it over the harness. I also moved the harness a little to lower the chance of it rubbing at all.
Although the short was at the wiper motor mounting bracket, it is fairly common for the front wiring harness to rub through and short out at the bumper mounting brackets on both sides.
These two pictures were taken from under the car looking up and towards the backside of the front bumper assembly