2nd truck batt

[Paul Clancy]

My 02 d/a 2500 has a 2nd underhood batt and I'm wondering what exactly it's purpose is...extra juice for truck accessories or power for the trailer or both? Nothing clear I found in the manual.

Cheers

[Bill Moncrief]

Hello
That's for cranking power to turn that massive diesel over tongue.gif
TOWERJAKE

[Colorado Kid]

It's so that after the glow plugs and intake heater do their jobs you still have plenty of juice left to roll it over and fire the injectors.