truck wont stay running

[63longfleet]

I hope someone on here has a idea of what is wrong here. I can start my truck it will idle just fine for a bit then die. After it dies it acts as if the Bat is dead ( no power at all). if you let it set with the key on for just a few min it slowly comes back to life, the "bell" starts off real quiet and just like turning up a radio it get louder till normal. then the truck will start again and start the process all over again. Thanks for any and all help, its my work truck and i cant have it down for long.

[speedygonzales]

You want to monitor voltage at a few points at different times.

Check the battery voltage before cranking, during cranking and after it fires up. As well as when it starts to die.

Voltage on a good vehicle battery should be 12.6VDC just sitting there with nothing on or running.

The voltage should not drop below 11VDC while cranking.

The voltage should stay at or above 14VDC while the engine is running. Period.

Monitor the voltage going to the ignition system if the above readings are normal.

Now monitor the key switch if the battery is acting normal.

See what is going in and what is coming out based on the numbers above.