Cold weather hit Denver last week, truck stopped working, no crank, no starter sound, good accessory power. Battery load tested, failed and replaced. Nothing. Starter load tested and failed. Replaced, nothing. Visual inspection of fuses good and switched starter relay around, nothing. Good power to solenoid positive post. Only 1.5v at ignition wire to solenoid during starting. Replaced ignition switch. Nothing. Multimeter tested relays, good. Tried starting in all gears, nothing.

What's next?