Fluctuating voltage gage

[Dixieman]

Fluctuating voltage gage, sometimes at 14 then drops to 12. Do these alternators charge as needed or should they be charging 14 + all the time.

 

[mb1500]

Year
Make
Model...

 

[Doubeleive]

Fluctuating voltage gage, sometimes at 14 then drops to 12. Do these alternators charge as needed or should they be charging 14 + all the time.

normal, unless it is dancing a jig while the blinker is on or something then it would be time to get a new battery

 

[Dixieman]

Thanks for the replies. sorry for the double post. cannot figure out how to delete.

2011 tahoe ls

 

[me51]

The ECM controls the alternator output, there are 6(!) different charging modes that the computer chooses from depending on temperature, electrical load, headlights on or off, ...

 

[Dixieman]

Guess I need to check battery cables and starter. Sounds like weak battery most of the time when cranking even with new battery

 

[swathdiver]

Guess I need to check battery cables and starter. Sounds like weak battery most of the time when cranking even with new battery

Look up the terms RVC and EPM. Lots of short trips will eventually drain the battery down. If that is normal, get a tender for it.

 

[Cantrepeat]

Fluctuating voltage gage, sometimes at 14 then drops to 12. Do these alternators charge as needed or should they be charging 14 + all the time.

I'm under the impression that newer alternator/charging systems actually shut off when the power is not needed. Thus, the gauge will show 12v or lower and when on show a normal 13-14v.

 

[Scoots]

I'm under the impression that newer alternator/charging systems actually shut off when the power is not needed. Thus, the gauge will show 12v or lower and when on show a normal 13-14v.

My 2012 Tahoe is also between 12-14+ I noticed on a road trip so replaced alternator since the Tahoe has 98,000 on it
After replacing for the first 10 min 14+ then dropped again to 12-13 for a few minutes?

 

[Scoots]

I'm under the impression that newer alternator/charging systems actually shut off when the power is not needed. Thus, the gauge will show 12v or lower and when on show a normal 13-14v.

Was this confirmed? That would be great
Thank You

 

[Doubeleive]

I'm under the impression that newer alternator/charging systems actually shut off when the power is not needed. Thus, the gauge will show 12v or lower and when on show a normal 13-14v.

Was this confirmed? That would be great
Thank You

read up^^^^^

 

[tom3]

For sure our '19 does lower the voltage at certain points while on the highway. I guess it saves wear on the battery from the over voltage, maybe gives 0.001 mpg increase.

 

[Scoots]

normal, unless it is dancing a jig while the blinker is on or something then it would be time to get a new battery

Thank You
Any Idea if the 2012 5.3 alternator will fit 2004 since i have a spare now and the 2004 has 160,00 on original Alt

 

[Doubeleive]

Thank You
Any Idea if the 2012 5.3 alternator will fit 2004 since i have a spare now and the 2004 has 160,00 on original Alt

if the 2004 is a 2 pin connector they yes it's a direct swap, if not then

2 pin 2006 + alternator. Don't throw it away!! - LS1TECH - Camaro and Firebird Forum Discussion

Conversions & Swaps - 2 pin 2006 + alternator. Don't throw it away!! - I just swapped the regulator in my alternator from 4 pin to 2 pin, so now it's like a 2006 or newer alternator. Why??? Because GM thinks it's better than the older 4 pin one and they must know something. Oh but everyone says...

ls1tech.com

 

[donjetman]

Fluctuating voltage gage, sometimes at 14 then drops to 12. Do these alternators charge as needed or should they be charging 14 + all the time.

on the 07+ we have this regulating system (Regulated Voltage Control or RVC) that basically controls the alternator when it sees more/less drain on the battery.

Here's a thread about the RVC: https://www.tahoeyukonforum.com/threads/figured-out-how-to-keep-steady-voltage.59534/

 

[Doubeleive]

on the 07+ we have this regulating system (Regulated Voltage Control or RVC) that basically controls the alternator when it sees more/less drain on the battery.

Here's a thread about the RVC: https://www.tahoeyukonforum.com/threads/figured-out-how-to-keep-steady-voltage.59534/

my wifes 05 has it as well