No light on dashboard no lights at all. Truck wont start

I'd start checking fuses. Also check the smaller feed wires on the batteries.

 

Find out if you have a battery shut off kenworth have automatic ones that go out and will cause issues also try to jump something 12v off your battery so u know you have power if you have good power at the battery check the wires on the ignition and if the ignition is seeming good may be your ecm.. have you had it tuned at all? Sometimes turning them up will cause the ecu to poop itself

 

Sorry I just seen it cranks.. the first thing would for sure be look at every fuse in the truck and under the hood.. wouldn't crank if the Batts were dead.. may be a fuse