Mazda Repair: Miata blowing fuses, electronic control unit, fuel pump relay

Question
I have a 1993 Mazda Miata that is blowing the main 30 amp fuel injection fuse in the engine compartment fuse block. At first the car would start and run about a mile and then blow the fuse but now as soon as you turn the ignition on it fries the fuse. I have unplugged the fuel pump but it didn't help. I removed the circuit opening relay (fuel pump relay) and it tested good. I even replaced it from my wifes Miata just to be on the safe side but the results are the same. I did the same to the fuel injection relay. Nothing has helped thus far. I unplugged the TPS because when it was running it seemed to stress the system when accelerating. No luck there either. Obviously I'm not an automotive electrican but I find most shops aren't up to speed either. So if you have any further suggestions I'd appreciate it. I'm just about to the smoke and burn test. AAHHHH!!

Answer
You have a dead short somewhere in the system.  Follow the harness from the injectors.  for test purposes disconnect the ground leads behind the fuel rail, also disconnect and reconnect the main ground lead (next to the dipstick).  Try the system with these undone to see if the issue continues.  Pull the main fuse box (under hood) and look at the harness under there.  Laugh, but squirrels and mice have been know to nest in these areas and they chew on wires.  Lastly pull up the carpet, passenger side and check for corrosion at the ECU (electronic control unit) plugs.

This is NOT a common Miata related problem so I will research the line by line sheets and let you know if I find anything else that may be helpful.  It does help to have a donor car around.