Correct battery voltage when running?
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Joined: Apr 2007
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From: LOST WAGES
Correct battery voltage when running?
I hope this is the correct forum----I have an '05 E-350 with a 6.0 and two weeks ago I replaced both batteries as its 2 years old and in a hot climate('vegas). last week while sitting at a light I noticed my battery guage a little low and when I got home pulled out my volt tester and it was at 11.9 volts at any rpm's......Bad Alt! right.. Just got it back from my dealer after $470 for a new alternator and I still have static battery voltage when its running @12.4 +/-. When I turn on my lights and front and rear a/c on high its @ 12.1 at any rpm. Does anyone know the correct voltage at idle? Or any thoughts on what the problem is. Thanks in advance for your wisdom!
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Joined: Dec 2006
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From: New Jersey
Just like these guys said 13.6 to 13.8 is pretty much normal at idle, 14.4 is pretty well max as said, under perfect conditions and on a high idle and with the engine off about 12.5 area. You have to take into account that heat plays a big part in your voltage readings, so if it is hot out this affects your batteries and alternator output ability, so the numbers may be slightly lower. As I see you have an E series, they also tend to run higher under hood temps, which doesnt help you.
Posting Guru
Joined: Mar 2006
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From: SoCal, SD CO. East
Originally Posted by poppie
that's high, more like 13.6-13.8 at idle,battery static voltage would be aprox12.6
Posting Guru
Joined: Jul 2006
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From: Republic of Texas
Try this . . .
The charging system takes 3 to 5 minutes to kick in on these trucks when started per vloney (ford tech here). Looks like 12+ volts during this time frame and then goes to 14.1 while running. Best to have the parts tested before total replacement (alt check and Battery laod test).
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Senior User
Joined: Oct 2005
Posts: 465
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From: Nesconset NY
First, make sure you have battery voltage at the pos. post of the alternator, if not check the connections at the distribution panel to the left of the radiator. if that is good check by the starter as this is the problematic starting point for the alternator positive wire. Next check the alternator plug, the orange wire should be live at all times, and the green wire with red tracer should come on and off with the key switch. If all of this checks out then I would say you might have a defective alternator. By yhe way, the correct charging voltage should be anywhere around 13.7 to 14.6V . Hope this helps .
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