Low Batteries
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Low Batteries
So I have noticed that my Batteries have been low each time my truck sits. Also my headlights have been dimming/brightening with acceleration. So I thought my Batteries were going bad. So I did some tests, I let my truck sit over night and tested the Batteries before starting they both were around 11 volts. @ idle no load 12.3, with load 11.7. @ 1500 RPM 14volts. With this I went to autozone and had the Batteries tested and the guy said that they are good but need to be charged and that the alternator was not charging right causing the low Batteries. The Batteries are about 3 years old.
So now Im not sure what to do.
So now Im not sure what to do.
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So I have noticed that my Batteries have been low each time my truck sits. Also my headlights have been dimming/brightening with acceleration. So I thought my Batteries were going bad. So I did some tests, I let my truck sit over night and tested the Batteries before starting they both were around 11 volts. @ idle no load 12.3, with load 11.7. @ 1500 RPM 14volts. With this I went to autozone and had the Batteries tested and the guy said that they are good but need to be charged and that the alternator was not charging right causing the low Batteries. The Batteries are about 3 years old.
So now Im not sure what to do.
So now Im not sure what to do.
Good luck!
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I have already charged them and they are good all day but the next morning they are low again. I drive the truck everyday
Cargo Master
Joined: Oct 2009
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From: South Carolina
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yes when I went to autozone I isolated them and had them each load tested.
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Hotshot
Joined: Mar 2014
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From: Douglassville, PA
I would charge them and pull the ground wires off of the batteries overnight and see what they're like in the AM. It would be a waste to buy new batteries and have a short somewhere that's sapping them overnight.
Hotshot
Joined: Jan 2011
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From: Puget Sound
This has the smell of a bad alternator, but you have to be careful when you check your voltages. If the alternator doesn't make about 14 volts at idle with glow plugs off, then that is an issue. You describe the volts being 12 at idle, and 14 at higher RPMs - my truck did this with confirmed good batteries just before I replaced the alternator and fixed the problem.
Posting Guru
Joined: May 2014
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From: Dustbowl, NV
My wife's Taurus was doing the headlight bright/dim thing, and the alternator was outputting like yours. Tested everything else, replaced the alternator out of anger(!), and the problem went away. 'Twas failing under load.
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So its been a few weeks since I installed the new alternator and everything is back to normal. It does not seem to have damaged the battery's at all. I also found a really good deal on amazon. If any one needs a alternator I would suggest taking a look.
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