Ignition dead short :(

[PARAGON]

I think some more details are needed. You did say that you have plugged everything back up and it's blowing the fuse?

Is blowing the fuse when you turn the key to on or is only when you attempt to crank?

Did you remove or change anything under the hood?

I am no mechanic or expert or anything but I think you have done something that is affecting the Hummer's Class 2 databus system. I think I remember somewhere that the databus system is short circuit protected to ground which is probably why you are blowing the ignition fuse.