No Battery Voltage To Cab

[stevel]

Started truck yesterday and ran fine. Shut it off. Went to restart no response,totally dead. Played with all wires at firewall ,battery, regulator. ignition switch, ect. with no response. Just about to give up tried one more time and it came back to life. Drove home and shut it down. Started a couple of times then nothing.
My first thought was the ignition switch is bad however would that effect the power to the lights as they don't come on.
My Battery and cables are new so I rule them out.