Must be a flu going around.
From my CB Radio.
From my CB Radio.
Service Battery Charging System
- Thread starter zach2011
- Start date
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Donovan
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I replaced my battery and it went away for a while. Put a new alternator problem solved. That was my experience.
scottg918514
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No warning light but issues. The other day, I was testing a rear defroster repair and had acc on (not started) and had a dead battery after 10 min. I had to jump start.
I hooked up a charge and charge to 100%. A few days later (today) I noticed the voltmeter fluctuating between 12 and 14 on an hour long drive (this may happen all the time, I was just paying attention today). I got home an decided to test the battery, said 56% charge,
I'd expect 100 after an hour drive. Bad battery? Or alternator. I don't know battery age, I bought used in 2013 (2007 truck) but no date codes marked on battery. However, it is a Carquest battery, so not original.
I hooked up a charge and charge to 100%. A few days later (today) I noticed the voltmeter fluctuating between 12 and 14 on an hour long drive (this may happen all the time, I was just paying attention today). I got home an decided to test the battery, said 56% charge,
I'd expect 100 after an hour drive. Bad battery? Or alternator. I don't know battery age, I bought used in 2013 (2007 truck) but no date codes marked on battery. However, it is a Carquest battery, so not original.
scottg918514
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New battery seems to have fixed it. With the old battery, I noticed the voltmeter start at 14.3 then drop to 12.3 or so and stay there. I put in a new battery and now the volts stay around 14.
Incidentally, the old battery was a CARQUEST with "Specially designed for European autos" on it. Not really sure how you design a battery for American, Japanese or European cars, but either way why would you put that in a GMC (prev. owner).
Maybe the European batteries work with 220 v.
scottg918514
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New battery seems to have fixed it. With the old battery, I noticed the voltmeter start at 14.3 then drop to 12.3 or so and stay there. I put in a new battery and now the volts stay around 14.
Incidentally, the old battery was a CARQUEST with "Specially designed for European autos" on it. Not really sure how you design a battery for American, Japanese or European cars, but either way why would you put that in a GMC (prev. owner).
Maybe the European batteries work with 220 v.
Voltmeter was staying around 14.5 constantly, but now dropping to 12.5-ish after a few minutes of driving.
Alternator?
jstutz101
Member
I've noticed my Voltmeter does that a lot while highway driving, think it might be normal.
It's normal. The charging system drops voltage when the battery is charged. It's supposed to put less strain on the alternator and help gas mileage.
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scottg918514
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Thanks for the replies, I put a new alternator on and still have the fluctuating voltage. I guess that is normal, oops.
mykon04
Member
I noticed this as well. I just bought a 2008 LTZ and the voltage will fluctuate from 14 to 12. That does make since about backing the charging off to save fuel mileage. It seems everything else is designed to save mileage so I believe it.
I read an article that solved this problem. It was the positive cable, inline, 175 amp fuse that's in a box bolted to the fire wall. It's the branch of the positive that goes to the alternator. The fuse cost about $4 from Autozone. Replaced it and haven't had the problem since. Hope this helps.
