2004 Trailblazer no crank. Help

So #2 Daughter has been driving my wife's old Trailblazer back and forth to school without issue. She stopped at a store and when she came out the thing wouldn't turn over. I came to her rescue and did the basic roadside stuff to no avail. The car came home on a flatbed and is now sitting in my shop taking up valuable hobby car space and time. Here's what I've found so far. Battery and connections good. If I jump the starter relay it cranks like a champ but doesn't even try to start. With the key in the start position I have power to the #17 position crank fuse and the #22 position ign e fuse. The start relay is not receiving power. The fuel pump does not turn on. The indicator light under the PRNDL dash indicator is not on no matter what gear you put it in. The gas gauge shows empty and doesn't budge. My darling daughter claims to have filled it the day before. I couldn't confirm this so I tried adding a couple of gallons to the tank but no change to the gauge reading. I'm suspecting it's the gear shift indicator switch on the side of the transmission. I unplugged it and cleaned the contacts but no change. My OBD scanner shows no codes. What next? I hate throwing parts at cars to fix them.

Does it have an alarm? Maybe try a different key?

Sounds like a transponder key failure. That will cause a no start condition with no codes. Try/get a new key.

Thanks for the suggestions. I tried a different key and nothing has changed. When my ignition switch went on my Saturn it got flakey before it failed. This one hasn't had the same issue and power is being sent from the ignition switch to the crank and ignition fuses but it isn't making it to the start relay. This makes me think the ignition switch isn't the issue but I've certainly been known to be wrong.

Does this have a mega fuse like the trucks do? They can corrode enough to cause huge problems. In fact there are a bunch of battery cable related issues in those trucks.

Have you tried disconnecting the battery to reset everything and rule out some software glitch?

Please keep the suggestions coming. I don't believe they have the mega fuse and there's very little voltage drop when I jumper the start relay contacts to crank the starter but it's something I'll check tomorrow. The battery sat disconnected overnight to try and eliminate a computer glitch. I'm a bit stumped on this one. Barring any revelations I'm picking up a used but tested shift position switch on Friday and I'll try swapping that in to see if it makes a difference. The plan with this car was to send it down the line in a couple of weeks since I'm replacing my DD and she'll get my current car. This thing has been flawless for months but I suspect it knows it's about to be bumped.

Maybe try a security relearn? Security Relearn

mazdeuce beat me to it. When you say no crank and no fuel pump, its most likely is security failure.

Transponder key failure is my first thought. When that fails, go to the relearn. If that fails, go through the troubleshooting for the receiver. If the transponder's receiver in the column isn't working, it won't start.

Check\clean grounds.