First remove and clean battery terminals, if you have a volt meter test battery voltage, 12.3v or higher is what you should see.
Your battery could just be bad, they last 5 to 7 years
The battery powers all the systems until engine is running, then alternator takes over.
Which is why "bump start" got engine/truck working, alternator was powering everything.
If it was the ignition switch then "bump start" wouldn't have worked.
After cleaning battery terminals follow each cable, GROUND TOO, to its connection, loosen and clean, make sure each has good connection.
As said if battery is older and your son was learning to drive a stick then there could have been many stalls and restarts, older battery, or corroded connections, would drain the battery of power fairly fast with several 150amp restarts per hour
Battery cables do wear out, they get corrosion under the plastic/rubber coating, this increases the resistance in that cable, so what starts off as 12volts at one end ends up as 8volts at the other end.
Ground cable carries same voltage as Positive cable, same amps, power must flow equally, bad connection or corrosion on either + or - lowers the voltage and amps
You can get some electrical tape and a razor knife, cut back cable cover, 1" to 3", and check it for whitish residue, if it looks good tape it up, look at BOTH ends of cable.
If you see the whitish corrosion, replace that cable
Look here for electrical diagrams: http://www.therangerstation.com/tech...rams/index.htm