2004 Sierra 2500 No Start - Solenoid wire no power when key turned
 

Just wondering if anyone has had this problem. No voltage at the little wire when you turn the key so solenoid doesn't pull in. I am hoping someone says it is just a fuse somewhere! The truck is seldom used these days, I am using an aftermarket key if that matters. I can and do start the truck by jumping the solenoid. About 120K miles. Anyone know where the wiring diagram is for this truck? I realize this isn't a Chevy truck, but I figure there are a lot more Chevys out there!

Thanks for any help you may be able to provide.

2004 Sierra 2500 No Start - Solenoid wire no power when key turned