Tahoe woes GM Merlin, any ideas???

[NX$paniard]

Heres the story: 2000 Chevy Tahoe Limited 5.7L Vortec 75k miles

Truck has been running excellent and was running great the day the problem occured. I parked, went into class for a few hours, came out and the truck wouldnt start. The fuel pump was not priming (making hissing sound). So I checked the fuses and the relay. Towed it home, dropped the Tank saw i was getting no voltage at the fuel pump connector.
So I went back to the Fuse/Relay panel and saw my AUX B 30A fuse was cooked. Ive replaced almost everything and still have the same problem, Fuel Pump is not priming or pumping/receiving power;
Ive replaced:
Fuel Pump-that sucked and was expensive
Fuel Filter
Fuel Pump Relay
AUX B fuse

everything cranks just fine, but the fuel pump isnt hissing, which tells me its not getting power...

What do I do now???? A friend of mine suggested possibly the ignition switch (not the one you put the key into) but supposedly there is some switch on the steering column..?? ( I have no clue what it looks like or what to look for) I feel the Fuel pump relay click upon turning the key, but still to no avail does the pump recieve power and prime or hiss.... Im runnin out of money and time and have no clue where to go next.. Hope someone can help.. THANKS!!!