Voltage dropping after driving

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LanceD

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Something I noticed in the past few days is when I start the engine, the voltage gauge will be above 14 and it will stay there for 10-15min but eventually drop suddenly to around 12. It seems to stay there until I restart and then it’s back above 14. Is this normal? I’ve never seen a vehicle stop the alternator output like this unless it’s broke. Does everyone’s PPV do this?
 

Doubeleive

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not sure about the ppv but the regular trucks have a battery maintenance system, the sensor is around the negative cable just below the battery compartment, you can unplug it to see if this makes any difference but I would have your battery tested just to rule that in or out.

sensor1.JPG
 

PG01

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not sure about the ppv but the regular trucks have a battery maintenance system, the sensor is around the negative cable just below the battery compartment, you can unplug it to see if this makes any difference but I would have your battery tested just to rule that in or out.

View attachment 190959

Not really a maintenance system its called rvc, regulated voltage control. It’s supposed to help with mpg. Basically alternator charges battery when it drops below a certain voltage, it can go up to as high as 15-15.5v down to 12v. It only charges battery when needed, like after first start which is what you are seeing and then drops off. If you unplug the sensor on the negative battery terminal your reading ‘should’ stay at a more consistent voltage, as long as your battery is good. Never hurts to test your charging system as doube said.
 

swathdiver

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It's normal and helps extend the life of the battery. My '06 Pontiac has this system and the original battery lasted 6 years and that was in Florida! In all my life I've never had a battery last more than two or three down here.
 

Bass

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Whew! I noticed this on a long drive back in October. My volts dropped way down. I was out in the woods, limited cell coverage and was worried about it all weekend. I had just put a new battery in prior to the trip and was thinking I was going to be screwed royally!
 

Polease

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Mine does the same thing. I took the battery to get it tested at AutoZone and they said it is fine.
 

Jerryrich0806

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Something I noticed in the past few days is when I start the engine, the voltage gauge will be above 14 and it will stay there for 10-15min but eventually drop suddenly to around 12. It seems to stay there until I restart and then it’s back above 14. Is this normal? I’ve never seen a vehicle stop the alternator output like this unless it’s broke. Does everyone’s PPV do this?
Mine does 2011 tahoe ppv and I have 2 optima yellow top batteries with and aftermarket alternator 370 amps.
 

Killmaster516

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So what can we do to make sure the voltage stays around 14.5. Should I just leave the headlights on when I want more voltage for my sound system or is there a way to manipulate the BCM so that it stays around that voltage.
 

Doubeleive

Wes
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unplugg the RVC sensor, but you should be perfectly fine if your battery is healthy with it plugged in. If you are concerned about audio power then get a cap
 

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