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12v on voltmeter

DRM796
Explorer II
Explorer II
Have a 2004 Silverado duramax. Driving down the road today and the voltmeter went from q4v to 12v with the battery light coming on and off. Never went below 1q and was able to drive another 110 miles. Got to the campground and after letting the truck sit for about 10 minutes it starts right up but still reads just 12v. Also noticed when ever the battery light comes on, if I get up to 2500 rpm the light will go out. Any ideas, alternator?

Thanks
2019 Alpine 3700
2016 Chevy 3500 High Country DRW Duramax
2012 Wildcat 313RE traded in 5/2018
7 REPLIES 7

Thunderbolt
Explorer
Explorer
Yup alternator. Had that happen on my 03. The reason you made it so far may be that the alternator itself is still charging. These alternators have a a separate circuit for the gauges and warning light. This can malfunction even if the alternator is still working. That's what happened to mine. It still requires replacing the alternator though.
Bryan
2003 2500HD Ext. cab short box
6.0 liter 4.10 gears, Nelson performance PCM 293,000 miles
98 K1500 4x4 heavy duty 1/2 ton (Sold)
6,600lb GVWR 5,280lbs on the scale empty
14 bolt rear diff. 3:73 , Tranny and oil coolers
380,000 miles.

DRM796
Explorer II
Explorer II
Thanks guys, found an Advance Auto Parts store 10 minutes from campground that had the alternator, replaced it and all is good.
2019 Alpine 3700
2016 Chevy 3500 High Country DRW Duramax
2012 Wildcat 313RE traded in 5/2018

azrving
Explorer
Explorer
Sounds like worn alt brushes are making intermittent contact with the slip rings. In a pinch tap on it lightly and it may charge until you can replace it.

time2roll
Nomad
Nomad
Alternator. Just run down get a new one and pop it on.

horton333
Explorer
Explorer
Ditto, the residual magnetism will sometime provide a little bit of power out at higher RPMs but check the alternator or have it checked ....
......................................

Ford Explorer or Chrysler 300C to tow with.
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agesilaus
Explorer III
Explorer III
Check the belt too
Arctic Fox 25Y Travel Trailer
2018 RAM 2500 6.7L 4WD shortbed
Straightline dual cam hitch
400W Solar with Victron controller
Superbumper

Mandalay_Parr
Explorer
Explorer
Sounds like alternator.
Jerry Parr
Full-time
2005 Mandalay 40B
Cat C7 350, 4 Slides
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2004 CR-V Toad
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