Blown PCM fuse - car won't start
 

I have a 2000 Grand Marquis (4.6L V8). While I was driving, the engine shut off and wouldn't start again. The PCM Maxi fuse under the hood (#12) was blown, and blew again when I replaced it. I know that fuse controls lots of sensors and other things, as well as the fuel pump. I unplugged the fuel pump in the trunk, and the fuse did not blow when I tried to start it (but obviously the car didn't start). Does this mean there is a short in the wiring to the fuel pump or that the fuel pump is bad, or not necessarily either?

While that means the wiring to where you unplugged it is good, so the problem has to be between where you unplugged it & the pump. Assuming you don't find a short between the pump & where you unplugged it, it would seem that the pump has gone bad. Hope you don't have a full tank of gas.

IIRC, these cars circuits are GROUND actuated by the ECM.

as opposed to Positive + or power actuated.

i know on a 1992 Grand Marquis i had, the fuse popped under the hood that ran fuel pump... ended up swapping pump and no more popped fuses... sometimes the pump gets stuff in it and gets over worked therefore drawing more power and overloading the fuse...