Sounds like a ground buss issue...have a read here...

https://www.gmforum.com/showthread.php?t=278980

I might have solved this problem. I did a search on fuel pumps and power windows and discovered that they're tied in together. There is a ground buss under the floor trim near the front of the driver door that gets corroded if wet or damp. Sure enough, mine was corroded. A few tugs on the wires brought everything back online, and I can no reproduce the start-no-start condition. I just have to figure out how to get the wires out off of the panel so I can clean them.

@Mike1995...I posted before I read yours, thanks...Thats EXACTLY the buss that is causing the issues. Thanks for that write -up. Now I know how to remove the metal buss and not the wires...This is huge for me...

Your very welcome!!

New here and looking for more info on the ground buss ideas?

Replaced crank and cam ps, fpr, icm, and tested batt, starter, alt, no security light displaying. If I had more info on the ground buss and what to check, test, replace.

The next time it won't start, there is a Shcrader valve on your fuel line above the upper intake. With the key on and the engine off press it down with something that won't damage it. Like a toothpick and see how the fuel pressure is. Power windows wouldn't be tied to its. Sometimes Vats keys go bad or get finicky, do you have more than one key?

https://www.gmforum.com/electrical-1...1999-a-303224/

doesnt have to be as bad as the one in the pic, mine was getting intermittent all you could see was the one wire starting to look melted

Actually, the power windows, power locks and I believe even the tail lights are tied to this common ground.

That ground is located, where? Drivers side under dash? I'm not near the car today...