05 Duramax Wouldnt start in the cold today

[Steve_m]

My 05 duramax has never had an issue with cold starts until today. (-17c). Not even that cold. It would crank just fine but wouldnt fire.. What could be wrong?

[06Voy]

Battery.

Have you ever changed the battery on that truck? If it is still the original battery Im sure its due for a replacement.

 

Edit:

You have 2 batteries since you have a duramax.

[Killerbee]

Yes, please charge the batteries, then try to start while still on the charger. That should isolate the glow plug energy as the cause, or exclude that suspect