Low voltage issue

[lance9386]

Why is voltage dipping well below 14 when the truck is running?? It's intermittent, it will go back up to normal at times..

[fondupot]

RTFM. If the needle is within the hash marks to either side of 14 volts. Its fine.

 

Straight from my owners manual:

 

"When the engine is running, this gauge shows the condition of the charging system. The gauge can transition from a higher to lower or a lower to higher reading. This is normal. If the vehicle is operating outside the normal operating range, the charging system light comes on."

Edited September 4, 2014 by fondupot

[MNDaveC]

I'd certainly be keeping a close eye on things if it starts fluctuating if there were no obvious electrical drains. Belt slipping? Low RPM?

[MikeNH]

This is normal. Look through the forum or read the manual.

 

Someone posts this question like once a week. ;)

[lance9386]

Thanks guys. I did RTFM... but.. I have never seen a vehicle unable to maintain 14.4V while running unless there was a huge draw on the electrical system. I find that at idle is mostly when this happens. At night with the headlights on it stays right above 14, where it should be. I just think that is very strange, but apparently it is by design.

[fondupot]

Thanks guys. I did RTFM... but.. I have never seen a vehicle unable to maintain 14.4V while running unless there was a huge draw on the electrical system. I find that at idle is mostly when this happens. At night with the headlights on it stays right above 14, where it should be. I just think that is very strange, but apparently it is by design.

 

Its a design element that comes from the fuel efficient alternators on these trucks. When the battery is within an acceptable range, the alternator is not engaged, this is less draw on the motor which saves fuel.

[lance9386]

 

Its a design element that comes from the fuel efficient alternators on these trucks. When the battery is within an acceptable range, the alternator is not engaged, this is less draw on the motor which saves fuel.

Thanks for the explanation! That is good to know.

[Crf450r420]

pin this thread and be done with this issue.

[MMC]

Saves fuel and extends battery life, GM's been doing this for years.

[Silver ice 6.2]

I haven't seen a pic.. and thought I would post.. here you go when I first noticed i said oh wow that's nice..lmao bit looked online and seen that it's normal. And yes that was my reaction at first

Edited July 5, 2015 by Silver ice 6.2

[20SierraL8T24]

I was just thinking about this because my truck is barely starting at times. My needle looks like above and I load checked the battery and it came back good.

[thejimmian]

does anyone with cooled seats notice a drop in seat fan speed when the voltage goes below 14v o nthe dash? I have recently noticed that when the truck turns the alternator off to save gas i basically loose the highest cooling level (fan speed is the same on level 2 and level 3). pretty annoying. i think it is the same story with the AC blower fan as well.

[KLRV6]

 

Its a design element that comes from the fuel efficient alternators on these trucks. When the battery is within an acceptable range, the alternator is not engaged, this is less draw on the motor which saves fuel.

And the battery will last longer by not forcing higher voltage on it when not needed. I was worried when I noticed it the first time.

[Kevin Gorczyca]

Here is my 2017 Denali with the 6.2L and 35,000 miles. Notice my two pictures have different miles on the trip meter. I was driving around for 4 hours yesterday morning and it stayed this low the whole time. This line represents around 12 v. You mean to tell me that this thing was in fuel saver mode charging at 12v for half a day? I’m having tons of electric problems on my truck and the dealer is using this as an excuse to not find the real problem. I’m also having transmission shuddering and slipping trouble, severe detonating on 93 octane (only when it’s cold and dry out), and front parking sensors and crash avoidance sensors throwing codes. Had front power seat and rear wiper not work intermittently too. Dealer is just making excuses but I think in my case this is NOT operating as designed. Can anyone elaborate on this?

Edited November 14, 2018 by Kevin Gorczyca
Added engine size and mileage

[Nasir222]

I have 2017 Silverado LTZ Crew Cab and it stays low in the daytime and jumps to normal range at night and I have a decent audio system upgrade and never had problems before... or noticed it. I noticed that when I push the audio in the daytime I have a clipping monitor that shuts the amp down when it hits clipping that only has happened when it gets close to the left side mark of the 14v. Weird because I would have never known if I didn't have the clipping monitor on my amp