Alternator voltmeter issue??

[Torched10]

Noticed in my 2019gt premium gt last week car voltmeter gauge bouncing between 12.0 and 14v as I'm driving I ng.
Throttle or gear doesn't matter.checked alternator voltage car in idle and its 13.6.battery is 12.6
Both are fine
But putting it in gear and drive Ing is when I get the voltage swings
Sitting at idle and giving it throttle car gauge reads 13v, not really high enough
In my garage at idle
Voltmeter with alternator running
Says 13.6v.so I'm guessing I have a voltage gauge problem. I hate to have dealer screw around with gauges in dash but being obsessive S I am don't know if I can just ignore the gauge
I could turn it off and pretend
nothing is going on.and as I said just Che king alternator and battery.
Voltage shows fine at 13.6 and 12.6 respe timely
Any thoughts or suggestions.thanks

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[NightmareMoon]

That's completely nominal behavior for the charging system. It only charges sometimes to maximize battery life or something, so perfectly normal for voltage to swing in that range while you're driving.

 

[ORRadtech]

I do believe that this is normal behavior. Battery charging is monitored by the Battery Monitor System (BMS) and controlled by the BCM. It adjusts based on load, state of charge, ambient temps and a few other factors with the objective of maximizing battery life.
I've never particularly noticed the phenomenon but I don't constantly have the voltage displayed.

 

[Cory S]

So other than you being concerned about values on a “display” Car operates normally right?

As long as the No load resting voltage of the battery is 12.5-12.7V, and at engine idle, your alternator shows 13.6V+……enjoy your car….

 

[Torched10]

So other than you being concerned about values on a “display” Car operates normally right?

As long as the No load resting voltage of the battery is 12.5-12.7V, and at engine idle, your alternator shows 13.6V+……enjoy your car….

Weird just came back from 30 minutes drive and voltage gauge showed 12v for most of trip.chwcked my battery and it's 12.6v. So I'm wondering how could my gauge show me 12v when battery is sitting at 12.6.agree on voltage varying during drive,but sitting at 12v gauge must broken when battery is 12.6 doesn't make sense

 

[Cory S]

Weird just came back from 30 minutes drive and voltage gauge showed 12v for most of trip.chwcked my battery and it's 12.6v. So I'm wondering how could my gauge show me 12v when battery is sitting at 12.6.agree on voltage varying during drive,but sitting at 12v gauge must broken when battery is 12.6 doesn't make sense

They never match. The system/display probably has a 15% variance in accuracy.

 

[Torched10]

They never match. The system/display probably has a 15% variance in accuracy.

Interestin. link


https://www.mustang6g.com/forums/threads/voltage-gauge-accuracy.91719/

 

[TonyHawk]

Weird just came back from 30 minutes drive and voltage gauge showed 12v for most of trip.chwcked my battery and it's 12.6v. So I'm wondering how could my gauge show me 12v when battery is sitting at 12.6.agree on voltage varying during drive,but sitting at 12v gauge must broken when battery is 12.6 doesn't make sense

normal behavior while driving. Your difference when you checked the battery is probably related to you checking it at the battery and where the system monitors the voltage. If you look at the data bus signals there are different places in the electronics that it monitors the voltage.

 

[Torched10]

Noticed in my 2019gt premium gt last week car voltmeter gauge bouncing between 12.0 and 14v as I'm driving I ng.
Throttle or gear doesn't matter.checked alternator voltage car in idle and its 13.6.battery is 12.6
Both are fine
But putting it in gear and drive Ing is when I get the voltage swings
Sitting at idle and giving it throttle car gauge reads 13v, not really high enough
In my garage at idle
Voltmeter with alternator running
Says 13.6v.so I'm guessing I have a voltage gauge problem. I hate to have dealer screw around with gauges in dash but being obsessive S I am don't know if I can just ignore the gauge
I could turn it off and pretend
nothing is going on.and as I said just Che king alternator and battery.
Voltage shows fine at 13.6 and 12.6 respe timely
Any thoughts or suggestions.thanks

Ok.brought it to dealer.service guy measured voltages at battery and alternator and they were fine.he said starting in 2019 Ford put a more voltage regulator in the alternator so it only provides a minimal charge if battery is charged.they did this for mpg reasons.they also put a red alternator alert so we are warned it may be failing.i didn't have that light so far.so I'm gonna take voltage gauge off my gauge screen so I won't see it.and test my battery voltage regularly to Make sure I'm good.at least I got rid of that battery that needs water what a pita.now have sealed battery 600cca duralast.

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