[SilentWolf]

On my 2007 NBS with the 5.3, for about the last week had been starting very "sluggishly". Turning over very slow, but does start. As soon as it fires up, my gauge shows just over 14 volts. It will stay there for 4-5 minutes, but then drops down to about 12v. No matter what I do with the lights or radio it stays right there.
This morning was the worst ( and has also been the coldest so far ). I know these new trucks have a monitoring system on the alternator output, but I don't have a clue if this is normal or not. I'm leaning toward it being a "going bad" battery?

 

[djlove]

Sounds like a battery, take it to an auto store, they will test it. Is it original? i think the acdelco's with silver label are original

 

[SilentWolf]

Yea, it's the silver label Delco, so more than likely the original, so more than likely it's time for a new one. I'm just confused by the voltage gauge dropping down to 12v so quick. If the battery is indeed going bad shouldn't it be staying up around 14v to try and charge it? Or is it because the battery isn't taking a charge anymore, and therefore it drops off thinking it's already charged?

 

[Redshiba]

The Alternator should be fine. Get a new battery and have the Alt. tested just in case.

 

[gmcultr]

I agree alternator sounds fine...

I don't want to seem like im pushing a specific autoparts store but advance auto has some ridiculous promocodes that take like 40% off your purchases and those codes work in batteries... I got my optima for way cheap that way... and no core charge and free installation. Just select it for store pick up.

Advance auto is useless unless you know what you're looking for exactly... but their promocodes are super sweet.

sent from my Verizon Wireless Galaxy SIII

 

[djlove]

Nice tip, I have a silver back that is going too

Sent from AutoGuide.com Free App

 

[GM Customer Service]

SilentWolf,

I am sorry to learn that you are experiencing an issue with your vehicle. I might not be able to give you any technical advice but I would like to look into this concern for you. Please private message me if I can be of any assistance.

Safe travels,

Jennifer T.
GM Customer Care