2001 Jimmy - No power & can't remove the key from ignition

Sounds like you have a bad ignition switch, not the lock cylinder but the switch itself. Electrical power should continue to go to the gauges and to the ignition module even with the key in the Start position.

and , did it start back up , did you put it back into park of neutral , is the battery dead , there could be a number of reasons , get back with more info

is the check light on? when you turn the key do you hear the fuel pump go on?

IF YOU JUST REMOVE THE ALARM THAT IS WERE THE PROBLEM LIES YOU HAVE THE MAIN IGNITION WIRE THE YOU MOST CONNECT FOR YOUR CAR TO START

I'm a little lost here, but if it will start on starting fluid, the ignition system is working.
Most V-6 GM trucks take at least 65psi of fuel pressure to start. Most aftermarket pumps don't do the job.
I would check the fuel pressure with a gauge next.

Sounds like your fan relay is stuck. Look in the engine area for your fuse box, there will be a list for the relays inside. Try pulling the one for the fan. Fans are powered all the time not just ignition on

take a good battery from another car that you absolutely know is good. Try to prime the motor twice turn the ignition to start position...do not crank turn ignition off turn ignition to start position and try to start

Not if you left your headlights on all night and completely drained the battery. if it is dead, try to jump it, if you get some sort of power with the jumpers attached, go buy a new battery.

Check the connections at the battery. Be sure they're clean and tight.

that a dead battery if our meter read full 6 amp is nothing they have 120 amp alternator try to boots it it should start move with our hand the cable sometime the therminal almost broken if not disconnect the therminal lock for corosion boots it let me know hope it fixya our post thanks pierre