Fuel pump issue?

[GMC_Typhoon]

On my '99 5.3, all of a sudden, the fuel pump stopped working. no sound when you turned the key, and the truck wouldn't fire. I pulled the bed, pulled the sending unit / pump assembly and dropped in a new one. It still will not do anything with the key on, or fire when you crank it over.

Stuff I've checked / verified.

1) The pump will move fuel from the tank to the fuel rail when "hotwired" using a spare battery; fuel comes out the schrader valve on the rail when opened.

2) The truck will not fire when the pump is hotwired and it is cranking over; getting fuel, but won't fire.

3) The fuel pump relay is good; switched it with the horn relay, and it works fine.

4) I cannot get 12V at the pump harness, and I believe I couldn't get 12V at the relay under the hood. Is there a fuse that feeds that relay?

When I pulled the bed, there is a block at the rear of the bed where 4 wiring plugs hook to. Does that need to be plugged back in for some reason?

I have checked the majority of the fuses; everything associated with ignition, etc. and they are all good. I cannot figure out why A) the fuel pump won't get 12V, and B) when you hotwire the pump to deliver fuel, why it won't fire.

Does anyone have a .pdf of the wiring diagram for a '99 X-cab Z-71, 4x4 5.3? Thanks.....

[GMMerlin]

Check the ECM B fuse.

[kev23]

My Brother in Law had same thing on his truck a week ago. Turned out to be a blown VCM/PCM fuse in the box under the hood. Good Luck.