Voltmeter Gauge Reading

[flyboyron]

I now have 1,700 miles on my truck. Yesterday driving to work, on the freeway I noticed my voltmeter showing to the left of the 14. The needle was just left of the 1 of the 14.

I thought that was odd since it usually has been at 14 or a little higher.

So when I went to leave work I turned the key on to see where the voltmeter gauge would read. It showed halfway between the first line which is 9 and the 14. So I turned on the engine and the gauge went slowly to the right of the 14. I figured it was ok.

So I jump on the freeway about 1/2 mile down the road and notice the gauge is now to the left of the 1 of the 14 and that just doesn't seem right to me.

I have to make a stop and figure when I get home I'll put my DVOM on it and see what it is really showing.

When I start the truck and drive it 30 miles home it stays to the right of the 14 all the way home. Seems normal now so I didn't check it.

 

I guess it was just a abnormality in the system?

 

I will keep my eye on it.

 

Anyone else have something like that happen?

[cerbomark]

100% normal. It s part of a fuel saving thing. I believe you can read about it in the manual.

[MS3DALE]

Subject: Information On Voltmeter Gauge Fluctuation Due To Regulated Voltage Control System And Concerns About Camper/Trailer Battery Charging

 

 

Models: 2005-2009 Cadillac Escalade Models

 

2005-2009 Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe

 

2005-2009 GMC Sierra, Sierra Classic, Yukon Models

 

 

Voltmeter Fluctuation Condition:

Some customers may comment that the voltmeter is fluctuating between 12 and 14 volts on their full size pickup or utility vehicle. Starting with the 2005 model year, light duty full size pickups and utilities are equipped with a new Regulated Voltage Control (RVC) system. This system reduces the targeted output of the generator to 12.6-13.1 volts when in "Fuel Economy Mode" to improve fuel economy. The generator may exit "Fuel Economy Mode" if additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems that usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted.

 

Camper/Trailer Battery Charging Concerns:

Some customers may comment that when towing or hauling a camper/trailer, the auxiliary battery for the camper/trailer will not stay charged. In most cases, this concern is blamed on the new RVC system. While the RVC system does reduce the generator's targeted output voltage to 12.6-13.1 volts when in "Fuel Economy Mode", this feature is bypassed if the tow/haul feature is enabled. With the tow/haul feature enabled, the RVC system will stay in "Charge Mode" and the targeted generator output voltage will be 13.9-15.5 volts, depending on the battery state of charge and the estimated battery temperature. To keep the generator in the "Charge Mode", use either of the following two methods.

 

• The first method is to use the tow/haul mode when towing or hauling a camper or trailer.

 

• The second method is to turn on the headlights, which will increase the generator's targeted output voltage to 13.9-14.5 volts.

[jrrod2004]

Subject: Information On Voltmeter Gauge Fluctuation Due To Regulated Voltage Control System And Concerns About Camper/Trailer Battery Charging

 

 

Models: 2005-2009 Cadillac Escalade Models

 

2005-2009 Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe

 

2005-2009 GMC Sierra, Sierra Classic, Yukon Models

 

 

Voltmeter Fluctuation Condition:

Some customers may comment that the voltmeter is fluctuating between 12 and 14 volts on their full size pickup or utility vehicle. Starting with the 2005 model year, light duty full size pickups and utilities are equipped with a new Regulated Voltage Control (RVC) system. This system reduces the targeted output of the generator to 12.6-13.1 volts when in "Fuel Economy Mode" to improve fuel economy. The generator may exit "Fuel Economy Mode" if additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems that usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted.

 

Camper/Trailer Battery Charging Concerns:

Some customers may comment that when towing or hauling a camper/trailer, the auxiliary battery for the camper/trailer will not stay charged. In most cases, this concern is blamed on the new RVC system. While the RVC system does reduce the generator's targeted output voltage to 12.6-13.1 volts when in "Fuel Economy Mode", this feature is bypassed if the tow/haul feature is enabled. With the tow/haul feature enabled, the RVC system will stay in "Charge Mode" and the targeted generator output voltage will be 13.9-15.5 volts, depending on the battery state of charge and the estimated battery temperature. To keep the generator in the "Charge Mode", use either of the following two methods.

 

• The first method is to use the tow/haul mode when towing or hauling a camper or trailer.

 

• The second method is to turn on the headlights, which will increase the generator's targeted output voltage to 13.9-14.5 volts.

 

 

any idea if Justin turns this off? or is it hardware based only?

[MS3DALE]

any idea if Justin turns this off? or is it hardware based only?

 

I never heard him say or mention anything about turning it off,My '07 doesn't fluctuate.

[jblakeney]

I now have 1,700 miles on my truck. Yesterday driving to work, on the freeway I noticed my voltmeter showing to the left of the 14. The needle was just left of the 1 of the 14.

I thought that was odd since it usually has been at 14 or a little higher.

So when I went to leave work I turned the key on to see where the voltmeter gauge would read. It showed halfway between the first line which is 9 and the 14. So I turned on the engine and the gauge went slowly to the right of the 14. I figured it was ok.

So I jump on the freeway about 1/2 mile down the road and notice the gauge is now to the left of the 1 of the 14 and that just doesn't seem right to me.

I have to make a stop and figure when I get home I'll put my DVOM on it and see what it is really showing.

When I start the truck and drive it 30 miles home it stays to the right of the 14 all the way home. Seems normal now so I didn't check it.

 

I guess it was just a abnormality in the system?

 

I will keep my eye on it.

 

Anyone else have something like that happen?

 

Perfectly normal so long as you have an alternator with a clutch pulley (i.e. you can not see the nut holding the pulley on to the shaft).

 

Jbo

[truckofwinandawesome]

its completely normal, and here is an excerpt from the 2009 Owner's manual to prove it:

 

"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."