How is it there are no specifications for a replacement battery in the Owner's Manual? There are 1/2 dozen batteries that come up on the AC Delco site for my vehicle.

I went out this morning and the van would not start ... just clicking. The battery is down from 14 volts on the dash meter last the vehicle ran to zip. I get 8 volts on my multimeter.

Where did the charge go?
The van has just been sitting since Friday late afternoon when I drove it last until this, Monday, morning - 2 3/4 days.

There have been not indications of electrical problems. No drain indicated on the dash volt meter, no starting problems, no dimming lights, no squeaking belts.

The van has a electrical shut down timer on the interior and exterior lights so that is not the assumed cause. The head lights were definitely OFF.
Have you experienced rapid failure with AC Delco batteries?

2003 Chevrolet Express 3500 Cargo Van; LQ4 6.0L V8

 

Looking at new batteries I expected to see a 14 volt battery since the dash electrical Volt Gauge read 14. But I'm seeing 12 Volt batteries.

Anyone have a reason why there would be a 2 Volt bump up on the voltage gauge?

I also see in one my repair manuals there is an Auxiliary Battery on some vehicles. But following the negative terminal down it is connected to the engine and not an Auxiliary Battery. I was thinking it might be responsible for the sudden death and hight Volt gauge reading.

2003 Chevrolet Express 3500 Cargo Van; LQ4 6.0L V8

 

Forgive my rush to understand ... I realize I was looking at the Volt gauge when the engine was running and indicating the output of the alternator.

With the ignition switch turned ON without the engine running a new battery reads 12+ volts.

I replaced the AC Delco with and Interstate MT-78 Mega-Tron II.

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Another question from hearsay ...
Will a weak battery put additional strain (wear) on the alternator?

2003 Chevrolet Express 3500 Cargo Van; LQ4 6.0L V8

 

Sounds like your old battery just got to the end of its life. They trickle down on their own when old....