Not sure if I asked this before, if I did, mind blown and forgot. Sorry in advance.

I've been doing a lot of searching to see what kind of running voltage others are seeing on their GMT800's. My 2006 Silverado SS is delivering just a hair over 15V running, like 15.1~15.2, which feels like just a bit too much. I'm used to seeing 14.0~14.2 on most vehicles, but this is my first GMT800 so I'm not sure if it's "normal" or not.

And I mean measured with a voltmeter at the battery with the engine running and all possible extra loads turned off like lights, stereo, A/C fan, etc.

Thanks!
Richard

 

Normally you should see about 13.6v to 14.2v .. 15.6v and above can do some damage to your electrical system.. I would have that checked.

 

My 2004 sees 14.2-14.3

 

Mine is usually 14.5v at first start (when its recharging the battery) and about 13.5 after a while.

Over 15 is not good, you may have a broken regulator in the alternator or something.

 

^^^ what he said... If you turn any loads on can you hear a high pitched whine?? My 99 would put out almost 16v at times and if any load came on it would start whining, ended up killing the battery overcharging it before i had money and time(at same time) to upgrade to the 145 amp... Oddly the new alternator was less than a reman!!!

 

Yeah I had a suspicion this was not normal. It's been running like this though for who knows how long; bought the truck a few thousand miles ago.

Gonna put a fresh battery in my voltmeter just to be sure, and check it again, before swapping out the alternator.

Richard

 

If going off stock cluster dont

 

Not sure what this means, except if you're asking whether I'm looking at the voltage on the cluster. Nope. Using a multimeter, at the battery. Never trust dash gauges.

Richard

 

personally wouldnt sweat 15.1 v, toss a load on the truck and watch it drop to 14.5

 

That's too high for a stock alternator and power system. Should be down around 13.8-14.2.

My custom alt runs at 14.8 because my idle load is about 80A haha.