I have a brand new Chevy Silverado Duramax and just this morning, I noticed something that didn't seem quite normal. After starting up, I engaged the windshield washer and noticed that the wipers were moving extremely slow. I looked at the volt meter and it was indicating zero charge voltage. Anotherwords, the meter was only reading the battery's normal 12 Volts whereas it should have been reading the charge voltage of approx 13.8 Volts with the needle up in the 14 Volt area of the onboard volt meter.

The vehicle is brand new with little over 2600 Km on the clock and my first instinct was to get it to the nearest dealer, however, as I drove it down the road, I noticed the voltage slowly climb to the normal 'CHARGING' position. I called one of the dealers and explained this to one of the tech reps and after consulting with another person, he said this was normal. I'm not a mechanic but I know that this is not normal. I also noted that after starting up, the voltage gradually climbs up and even goes slightly higher than where it normally should be and after a few minutes, it drops down to the normal position. The tech said that if there was a failure of the charging system, a warning message would appear on the display indicating this. I have not seen anything yet. I'd hate to be out on the highway and have a failure whereby the truck shuts down!

Just wondering if anyone has seen this sort of thing before.

Thanks for reading......
Pat in Ottawa, ON

 

Its normal..the gauge will fluctuate quite a bit on an 07

 

Thanks for the reply Argon...I checked with several other sources and they all say the same thing you have said and that it is normal.

Pat

 

I didn't have time yesterday to fully reply..but here it is..
07's have "Voltage on demand"...to increase mpg...the alt will actually cease to charge when its not needed to reduce engine load...then suddenly kick in and charge its *** off.