Alternator issue?
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Senior User
Joined: Jul 2012
Posts: 122
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From: Northwest Indiana
All better now! New alternator and batteries are in. I got the batteries replaced under warranty as my father-in-law was concerned about the one battery that had run down to being completely flat, so we replaced them both. Serial numbers on new batts are within a few digits of each other meaning they are from the same production date/run. Getting ~14.6v on the battery posts now when it's running! 
Thanks for everyone's help!
Thanks for everyone's help!
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
If you are seeing 16 volts anywhere (measured with your cal'd Fluke), something's just wrong!
Maybe time to check the ground point integrity for your regulator inside that alternator, 'cause it seems to be floating up.
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Joined: Jan 2008
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I don't know about ford, but the wife's dodge measures anywhere from 14.2 to 15.9 depending on how low the batteries are. The service manual states you can see as much as 16.4 vdc. I have never seen it go that high, but for dodge, it's within the norm, so I assume it is similar for ford as well.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
How is that measured?
If by a gauge on the instrument panel, I wouldn't think it hugely accurate.
If, however, it is in a procedure in their maintenance manual, measured by an accurate meter, I find it unusual.
Lead/acid batteries shouldn't see that high voltage for any period of time, as it causes excessive gassing, with the resultant loss of electrolyte.
OTOH, they may have a variably-excited field, which COULD do that.
Our trucks (we ARE talking about our trucks, aren't we?) have a fixed set point of 14.4 volts. They are identified by a gray-on-gray (gray cover on gray body) regulator.
Pop
If by a gauge on the instrument panel, I wouldn't think it hugely accurate.
If, however, it is in a procedure in their maintenance manual, measured by an accurate meter, I find it unusual.
Lead/acid batteries shouldn't see that high voltage for any period of time, as it causes excessive gassing, with the resultant loss of electrolyte.
OTOH, they may have a variably-excited field, which COULD do that.
Our trucks (we ARE talking about our trucks, aren't we?) have a fixed set point of 14.4 volts. They are identified by a gray-on-gray (gray cover on gray body) regulator.
Pop
Senior User
Joined: Feb 2013
Posts: 145
Likes: 0
From: Long Island
How is that measured?
If by a gauge on the instrument panel, I wouldn't think it hugely accurate.
If, however, it is in a procedure in their maintenance manual, measured by an accurate meter, I find it unusual.
Lead/acid batteries shouldn't see that high voltage for any period of time, as it causes excessive gassing, with the resultant loss of electrolyte.
OTOH, they may have a variably-excited field, which COULD do that.
Our trucks (we ARE talking about our trucks, aren't we?) have a fixed set point of 14.4 volts. They are identified by a gray-on-gray (gray cover on gray body) regulator.
Pop
If by a gauge on the instrument panel, I wouldn't think it hugely accurate.
If, however, it is in a procedure in their maintenance manual, measured by an accurate meter, I find it unusual.
Lead/acid batteries shouldn't see that high voltage for any period of time, as it causes excessive gassing, with the resultant loss of electrolyte.
OTOH, they may have a variably-excited field, which COULD do that.
Our trucks (we ARE talking about our trucks, aren't we?) have a fixed set point of 14.4 volts. They are identified by a gray-on-gray (gray cover on gray body) regulator.
Pop
Also to comment on the reman vs new thing. I might be a little biased here since I run a shop that does alternator and starter remanufacturing, but I would take the reman over new any day of the week. I could show you guys some of the utter garbage coming from china that is put in these new units, and it's just depressing. The failure rate on the new ones is actually pretty high, so at the end of the day, a quality reman is the better option, even if it sometimes costs a few extra bucks. It's worth the peace of mind.
With that said, some of the reman stuff can be crap as well. NAPA units, USA industries and the like come to mind, I've seen some laughable things in their units.
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The highest "set point" I have ever seen for an alternator is 14.7 volts. More typically they are 14.4.
If you are seeing 16 volts anywhere (measured with your cal'd Fluke), something's just wrong!
Maybe time to check the ground point integrity for your regulator inside that alternator, 'cause it seems to be floating up.
Pop
If you are seeing 16 volts anywhere (measured with your cal'd Fluke), something's just wrong!
Maybe time to check the ground point integrity for your regulator inside that alternator, 'cause it seems to be floating up.
Pop
14.6V on the posts will lose some power before it gets to the usage point due to the resistance of the connections in between.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
Also to comment on the reman vs new thing. I might be a little biased here since I run a shop that does alternator and starter remanufacturing, but I would take the reman over new any day of the week. I could show you guys some of the utter garbage coming from china that is put in these new units, and it's just depressing. The failure rate on the new ones is actually pretty high, so at the end of the day, a quality reman is the better option, even if it sometimes costs a few extra bucks. It's worth the peace of mind.
With that said, some of the reman stuff can be crap as well. NAPA units, USA industries and the like come to mind, I've seen some laughable things in their units.
With that said, some of the reman stuff can be crap as well. NAPA units, USA industries and the like come to mind, I've seen some laughable things in their units.
Find a quality local rebuilder, and use HIM to make your OEM units like new again!
Now, Chris, want to comment on the Mitsu PLGR versus Nippondenso OSGR starter debate, and NOT those Chinese units, but the OEMs, and the quality rebuilds thereof?
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