2007 Silverado 2500 diesel - tried starting and just clicking and buzzing. Has two batteries so hard to believe both are dead?

 

Are the battery terminals full of corrosion or have loose connections? Is the alternator charging properly? There are many things that can cause dead batteries.

 

Thanks for your feedback. I replaced both batteries and all's well. I guess I thought both batteries bad at the same time was slim chance, so thought might be something elase.

Thanks Much!

 

My dad has a 2007 Silverado 2500 Duramax Diesel.
My question though, i like the Silverado 3500 but dont know which one is better the gas or Diesel one. Which is better, fuel economy wise and which will last longer, keeping it well maintained?

3500 Silverado with Diesel Duramax with Allison transmission or 3500 Silverado with Vortec Engine?