No power to any electical unit just starts

SOURCE: Ignition key cannot be removed, engine cannot be

check battery and replace if required.

SOURCE: The other day I went

Did you touch the acceleration pedal, if you did it could be fuel build up. Does this happen all the time when you start the truck. If so it could be valve seal that are leaking.

SOURCE: i have a dead radio in my 2004 envoy. no

there may be a small inline fuse at the back of the radio itself.....you will see it when you remove the radio, this is to prevent overload

SOURCE: Electrical Problem - dead battery

Sounds to me like you may need a new rectifier put in the alternator,a shorted diode in the alternator could be powering up things that should go dead with the key in the off position.To prove this,instead of pulling the fuse,take the plug out of the alternator and if all is well,you have your answer.

SOURCE: What does reduced engine power light mean

this model has what they call fly by wire.. no accelerator cable. If the computer detects a problem in the thottle system it will not allow the engine to accelerate and will show reduced power and possibly set a check engine light. The dealer usually wants to replace the throttle assembly which is very expensive and usually un nessesary.
I have had a lot of succes with just cleaning the throttle plates real good.