Battery Light
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Laughing Gas
Joined: Feb 2011
Posts: 991
Likes: 6
From: Newberry Springs, CA
Battery Light
Hi All,
Need a little guidance. I have an '06 F-250 with the 6.0L engine. Recently on a long trip my battery light came on. Naturally the second I got home I threw the batteries on the charger, but both seemed to be in pretty good shape (one @ 75%, one @79%). I reinstalled them and went on my merry way.
The light keeps coming on, but it does not stay on all the time. It seems intermittent with no rhyme or reason to why it comes on or goes off. I charged the batts again last night, one was at 78%, the other at 80%. It's been a couple of weeks since I charged them the last time so i would suspect if it was an alternator issue they would have charged down more, or even gone dead. Since the alternator is a pretty penny, I thought I might throw it our to the braintrust before I replace it.
Any help would be much appreciated.
Need a little guidance. I have an '06 F-250 with the 6.0L engine. Recently on a long trip my battery light came on. Naturally the second I got home I threw the batteries on the charger, but both seemed to be in pretty good shape (one @ 75%, one @79%). I reinstalled them and went on my merry way.
The light keeps coming on, but it does not stay on all the time. It seems intermittent with no rhyme or reason to why it comes on or goes off. I charged the batts again last night, one was at 78%, the other at 80%. It's been a couple of weeks since I charged them the last time so i would suspect if it was an alternator issue they would have charged down more, or even gone dead. Since the alternator is a pretty penny, I thought I might throw it our to the braintrust before I replace it.
Any help would be much appreciated.
Logistics Pro
Joined: Nov 2004
Posts: 4,795
Likes: 47
What are the percentages you list of?
I’ve always checked batteries based on the simple voltage, then maybe a load test.
Alternator may not be charging properly. I’d see what the voltage is with the engine off, and then on. If the off voltage is 12.5/12.6 and the on voltage is around 14.5, then it would appear that the alternator is charging properly
I’ve always checked batteries based on the simple voltage, then maybe a load test.
Alternator may not be charging properly. I’d see what the voltage is with the engine off, and then on. If the off voltage is 12.5/12.6 and the on voltage is around 14.5, then it would appear that the alternator is charging properly
Hotshot
Joined: Dec 2014
Posts: 17,832
Likes: 3,119
From: Jersey Shore
The battery light was mislabeled. It is triggered if the alternator is not charging correctly, either improper current output or a diode is bad and there is some AC leaking in. Since the batteries are not getting recharged, it’s not diodes.
The first thing to check is if the connections are an issue, then if the fusible links are gone. On and off typically is a tell that the brushes are worn or stuck in the holders. If it’s just the brushes, a replacement voltage regulator can solve the problem as long as the segments are not damaged.
I’ll throw in my video that you might not need.
The first thing to check is if the connections are an issue, then if the fusible links are gone. On and off typically is a tell that the brushes are worn or stuck in the holders. If it’s just the brushes, a replacement voltage regulator can solve the problem as long as the segments are not damaged.
I’ll throw in my video that you might not need.
Senior User
Joined: Jul 2014
Posts: 435
Likes: 2
From: Bloomfield, NM
I just did the same dance. 3 super dutys in a row I've owned that did the same thing. Intermittent charge light, charge batteries, clean and tighten cables, then finally break down and change the alternator and it goes away. Just my experience.
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Mountain Pass
Joined: Jan 2008
Posts: 211
Likes: 0
From: North West Arkansas
I've danced this dance as well. Chased the interment battery light for a few months doing diag on a bunch of different circuits. I even replaced the dashboard and the problem didn't go away. Got tired of chasing it and just learned to live with it.
UNTIL.............due to an unrelated issue, ended up replacing my alternator........POOF, away it goes and all is right with the world again. I can't explain it. I just know it went away the second I replaced the alternator.
FWIW: if you end up getting a replacement from one of the local part houses, make SURE they test the thing 3 times before you leave the store. I went through 3 OBF before I found one that passed testing 3 times....
The next time my alternator takes a dump, I'm seriously going to consider getting one of the aftermarket models from FicmRepair.com.
https://www.ford-trucks.com/forums/1...-system-3.html
UNTIL.............due to an unrelated issue, ended up replacing my alternator........POOF, away it goes and all is right with the world again. I can't explain it. I just know it went away the second I replaced the alternator.
FWIW: if you end up getting a replacement from one of the local part houses, make SURE they test the thing 3 times before you leave the store. I went through 3 OBF before I found one that passed testing 3 times....
The next time my alternator takes a dump, I'm seriously going to consider getting one of the aftermarket models from FicmRepair.com.
https://www.ford-trucks.com/forums/1...-system-3.html
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