ECM-B fuse blown
 

I have a 96 GMC 5.7 vortec that keeps blowing ECM-B 20amp fuses the truck will just quit and then if you let it cool down for about an hour it will let you put in a new fuse without it blowing and run for about another hour. Heres what ive done- I replaced the fuse with a fliptop off a beer can and that got me off the highway( I noticed when i did that the fuel guage pegged past full), i tried a 30 amp and it blew with just the ignition on, i replaced the fuel pump relay and that did nothing, i played with the wires and havent found a short anywhere on the top side. Any ideas whats going on?? by the way if i get it running and just let it sit and idle it will still blow the fuse. The fuel pump isnt that old could it be the pump wiring??

RE: ECM-B fuse blown
 

Have you had any tranny work done lately? If so inspect the harness over the trans that supplies the o2 sensors for a short. Have had 3 customers in last 2 years with same problem.