My darn truck won't crank

[EdGein72]

My 09 Sierra 4.3 won't crank. I turn the key and nothing. I checked online and youtube said try finding and swapping relays. Didn't change. Another said try disconnecting the BCM and grease it and reconnect it and that didn't work. There is no click, the truck doesn't even try to turn over. Everything lights up like normal on the dash. The radio works fine. I even tried jumpstarting it and still nothing. This has never happened before. I don't know what else to try except take it to a shop. Things were so much easier before all this computer crap. Probably the simplest thing but I don't have a clue. Any incite would be much appreciated. Thanks in advance.

[CamGTP]

Take the battery out and go get it tested.

[BarryKH]

Disconnect the battery and leave it for 30 minutes or so. Reconnect it and try to start it.

[swathdiver]

Maybe it's an old school failure, the starter solenoid died?  You can throw parts at it or put a Tech-2 on it and find out in moments what is wrong.

[asilverblazer]

Make sure the engine is grounded well to the chassis/battery.

[SmokChsr]

Don't forget the silly things, make sure the transmission knows it is in park, also try starting in neutral. There are also anti theft circuits that may cause this, be sure to lock and unlock with the fob.