I have a 2005 Duramax recently all of the power features quit working, the radio won't turn on with the key, none of the gauges work. If I leave the batteries hooked up it will drain the batteries. When I try to start it it fires up and immediately shuts back off. I've checked all the fuses and the wiring harness in all the usual troble prone spots and have not had any luck. I have checked the fuel system and it appears to be fine. Any help, advice, ideas, or thoughts would be greatly appreciated!