Volt Meter drops below 14 on a new Tahoe

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swathdiver

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I bought my new Tahoe (2020) a few months ago and today I had to make a 300 mile trip down the interstate. I never really paid attention before but it always seemed to me it was indicating 14 (straight up) but Im sure it moved some. Today I noticed it was move between the straight up position and what I guess would be around 11, it did this several times and I was so paranoid about going dead I didnt even stop for a nature break. If you own a 15 or newer do you ever see your amp meter dropping from te 14 (straight up) to about the 10 or 11 as you go down the highway? It could be its totally normal and I never noticed it but it sure seems odd.

There are detailed explanations on how this system works in the shop manual and the GM Upfitter's manuals. Look up the key words EPM (Electric Power Management) and RVC (Regulated Voltage Control).

For those of you with radio controlled cars, planes, boats, etc. this is basically a smart charger built into your truck, pretty cool.
 

iamdub

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Yup- cool system, indeed.

It's to extend the life of the alternator and battery. A full battery doesn't need to be charged and an alternator doesn't need to be loaded down charging a full battery. Also, a battery needs to be cycled, so you'll see it being discharged and charged on a long trip.
 

TheAutumnWind

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my gmt400 with an overdriven ad244 upgrade even does it. I never see it below 13 or so though. I'm sure its a more rudimentary deal than whats on the newer trucks, but it has a signal wire that reads battery/system voltage and varies the load on the alt.
 

drakon543

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i have a forklift at work with a 1966 chrysler 225 slant 6 a chevy alternator and a 1976 ford f100 voltage regulator in it. who needs all this fancy stuff just cobble something together until it works right!
lol
 

Captain Insaino

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This is exactly why the auto industry has been dumbing down accurate gauges with feel good-o-meters that don't move until they are out of normal range. They found out some people actually pay attention to them and ask questions they don't want to be bothered with.
 

iamdub

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This is exactly why the auto industry has been dumbing down accurate gauges with feel good-o-meters that don't move until they are out of normal range. They found out some people actually pay attention to them and ask questions they don't want to be bothered with.

So, next time a cop asks me if I knew how fast I was going, I can honestly and accurately answer "right where it felt good, officer".
 

mbelluardo

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I bought my new Tahoe (2020) a few months ago and today I had to make a 300 mile trip down the interstate. I never really paid attention before but it always seemed to me it was indicating 14 (straight up) but Im sure it moved some. Today I noticed it was move between the straight up position and what I guess would be around 11, it did this several times and I was so paranoid about going dead I didnt even stop for a nature break. If you own a 15 or newer do you ever see your amp meter dropping from te 14 (straight up) to about the 10 or 11 as you go down the highway? It could be its totally normal and I never noticed it but it sure seems odd.
My 2015 Denali xl does that all the time , I also thought it was kinda strange. I’m glad someone brought it up. Just talked to a mechanic friend and yea it’s totally normal.
 
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