Jump to content

Recommended Posts

When I start my truck my volatge goes up to just above 14 volts. After about 7 - 10 minutes, the voltage goes down to exactly 12.7 volts. The truck still runs fine and the volts dont move again untill I re-start the truck. Is my alternator going bad or is this normal for a 2007 Silverado 5.3?

Share this post


Link to post
Share on other sites

Its normal....

 

xTooltipElement

Service Information 2007 Chevrolet Silverado - 4WD | Sierra, Silverado VIN C/K Service Manual | Document ID: 2394671

--------------------------------------------------------------------------------

 

#07-06-03-009B: Information on Voltmeter Gauge Fluctuation Due to Regulated Voltage Control System and Concerns About Camper/Trailer Battery Charging - (Feb 5, 2010)

 

 

Subject: Information on Voltmeter Gauge Fluctuation Due to Regulated Voltage Control System and Concerns About Camper/Trailer Battery Charging

 

 

Models: 2005-2010 Cadillac Escalade Models

 

2005-2010 Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe

 

2005-2010 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 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.

Share this post


Link to post
Share on other sites

Excellent info Rich. I didn't know that the GM system operated this way.

Share this post


Link to post
Share on other sites

so does your truck still do this? or did you fix something?? I bought a 07 sierra 3 months ago and it read 14 for those months then i replaced the battery and ever since then in is constantly up and down most of the time under 14 and latelyt been reading 12.7 also. thanks

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Popular Now

×

Important Information

By using this site, you agree to our Terms of Use.