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Stock alt + 2 AGM idle voltage


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Hey just want to know if a resting or idle voltage of 14.0v to 14.2v without any load is fine? Or should it be higher? 

 

Car has a 120amp stock alt and 2 agm batts. 1 starting and 1 in trunk. Both medium to large size and fully charged. 

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Both batts are connected and this was done today i guess while engine is cold 

 

I was told since both batts are connected parallel that the car sees it as 1 bank. So the voltage im seeing is for the 2 batts together as 1 not one or the other. 

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Did you connect the dmm to the battery under the hood or the battery in the rear? First read the alternator directly on the positive post of the alternator and the negative ground bolt of the alternator and compare that voltage to the voltage of the under the hood battery beside it and if that battery is reading lower then that battery has a weak positive connection or bad ground and then test the rear battery the same and if it reads lower then it has a bad ground or a weak positive connection. Make sure on the positive connections that the fuses are snug and tight and well connected and make sure the grounds on the battery are short, 18” or smaller, and grounded hard. Too long of a ground will result in lower voltage, no matter how hard and good it’s grounded. If your alternator is reading 14.2 then the batteries and connections are fine and that’s just that alternators voltage. Factory alternators voltages range from 13.8 to 14.6. So don’t worry. Just grab a dmm and start checking things out. 

:stupid:“How can we help you?”
:guido:
“And don’t forget to tell them that 
the customer isn’t always right.”

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I didnt do any of that. I have a voltmeter in the car and i just follow that. That reads 14.2 at cold start up and idle. Upon driving it can range 14 to 14.3

I use to be higher like 14.3 to 14.6 cold start idle and driving for the first few mins then it would settle to 14.0 to 14.3

 

I guess its ok where im at..i just psychologically feel more at ease with 14.3 and above 

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K something is def wrong. No system playing with mild ac on. Voltage is jumping from 13.8 to 14.2 driving at 3k rpm and up for an hour. 

It never did this before. Voltage always rose when rpms went up and it would stay steady not jump around. I think i got a loose or corroded wire or terminal or perhaps alt is starting to die. I was pushing 2500rms on stock alt. Maybe that fucked it up. I gotta dig deeper and figure this out

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