97 blazer won't start

Really strange. Turn the key to crank and the gas gauge indicator pegs to the right. Indicating a full (plus) tank. I did notice that the fuel pump does not come on. It cranks very strong but won't start. Probably not getting any fuel because it won'y start? But why?
Here about 8 months ago I replaced the switch under the key switch (little black box with a pig tail and all the little contacts in it) in the column. And all my problems were solved. It would shut down while driving, the lights would go out while driving. A real nightmare, but changing out that little switch box under the key switch in the column did the trick.
Just wondered if that little switch might be acting up again?
Cnonstructive comments.....

Thanks

GT

Check fuse boxes for all key on 12 volt power.

Does the engine have spark to more than one spark plug?

Check fuel pump power to relay and to fuel pump.

Lot of no start post on here.
Look some of them over for ideas.
MT

Fuel gauge pegging out might be a clue. When the fuel gauge loses ground, it reads over full. The fuel gauge and the fuel pump use the same ground. There is a splice pack near the rear bumper, check the connections to it and to the frame where it grounds.

I will check that ground. Got spark and fuel, just no fuel to the cylinders because the fuel pump does not work. At times (very few) the vehicle will start. I can usually tell if it will start if as I turn the key I (1) hear the fuel pump come on and (2) the gas gauge reads normal. If however I step on the gas while idling in park, the "service engine" and "ABS" lights both come on and the vehicle will stall. It was sending codes that 3 - O2 sensors were bad a couple of weeks ago. A friend of mine recommended a fuel filter change and the codes went away. Now I have the no start dilema... Oh well, I'll keep plugin'

Thanks guys

GT