2003 2500HD Silvarado Battery light?

Hi , I have a 2003 2500HD Silvarado PU. The Battery light keeps coming on and remains at different levels of intensity [ the brightest when the vehicle is sitting ] The dealer put a new battery in and the light stayed
off for about a half hour , for the ride home. The Voltmeter stays around 14V , and charging appears normal, the vehicle also starts and runs fine. I would think if there was a problem in the charging system that the Voltmeter would read low [ around 9V ] Does anyone know, specifically, what the battery light indicates ? Could this be an overly sensitive light and just a false alarm? Anyone have any idea what could be going on? Thanks..... Kevin Davis
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Normally if the battery light is on the alternator is shot. Take it back to the dealer and tell him to stop guessing and fix it.....

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Yup,, In most cases it's the alternator. It doesn't mean that it is completely shot, be will be with time.

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The battery light is controlled by the pcm in this vehicle.... I seriously doubt the alt is bad... There is a sense wire coming from the alt going to the pcm... this is monitored by the pcm to see if there is an issue... I have had a few with this problem and it can be difficult to correctly diagnose,although a battery wouldn't have been my first choice... If the pcm sees a problem, then it tells the cluster via the class2 data line to illuminate the battery light... I would bring it back to the dealer, but I wouldn't have a panic attack if they took a while to get it in... as long as you are seeing good voltage(14v) then you won't be stranded... 1 was a wiring issue(ran new wire from pcm to alt), and the other one ended up being an internal problem in the pcm.... ....if you need more specific info, let me know.... Bobo

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As a retired GM service manager it is saddening to see that an owner of a new truck has to resort to posting here for help with a new vehicle warranty repair problem. If I were running a service dept. that this issue pointed to, I would be embarrassed and bend over backwards to resolve the problem.

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On this vehicle, the light is turned on or off by the instrument cluster, based on messages from the powertrain or body control modules that tell it the charging system voltage is below 11 volts or over 16 volts. It should be either full on or full off, not varying in brightness. I would put a voltmeter on the battery and see what it reads with the engine running, the dash gauge is not that accurate. It should be around 14 volts or so with no accessories turned on. If the charging system voltage is normal, I would suspect something screwy with the instrument cluster.
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