Alternator Overcharging?
Elder User
Joined: Aug 2007
Posts: 502
Likes: 0
Is there any way you can load test these batteries where you live? If not then you can do a poor mans load test with your meter hooked to one battery at a time. Watch the volt drop while you have lights,heater fan turned on engine not running.Check to see if the volts drop below 9volts then check other battery same way. You didnt say anything about the truck starting hard so its good to load test the batteries anyway.Anything past 14.8 volts your boiling the batteries with engine running. Did you check all battery connection and grounds? What kind of batteries do you have?
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Elder User
Joined: Oct 2004
Posts: 916
Likes: 0
From: Hazelton,BC Canada
I drove arounda bit to get the volts up in the scary range, and it was up at 16 anda bit and then when ideling fora bit drop back down...I had a 2 hard starts in as many days before the day before the alternator went, right now it seems to start just fine. I dont even know what batteries are in there they havnet given me problem in the past, the are the stock ones I am guessing...isnt there like a voltage regulator or something to that effect? that could be messed up?
Elder User
Joined: Aug 2007
Posts: 502
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Yes it could have a bad internal voltage regulator the regulator is inside your new alternator though. You need to really have those batteries check out before you condemn the alternator.OEM batteries are past due on replacing.16 VOLTS is not good.
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Elder User
Joined: Oct 2004
Posts: 916
Likes: 0
From: Hazelton,BC Canada
I put on lead on the alternator and one on the ground and its putting out like 14 something. i dunno if that means anything. maybe I'll just put 2 new bats in there and see if its any different
Logistics Pro
Joined: Mar 2002
Posts: 3,881
Likes: 84
From: Wake Forest, NC
Did you pay for a charging inspection? If not, or they did not say/state they included one for free, don't assume they did anything.
Simply, KISS, the alternator is faulty. Could be an intermittent connection in the alternator regulator causing it to charge high. Definitely need to verify with a standalone voltmeter.
I don't know about the 2000, but the 2002 and 03, disables charging until the GP's cycle off and limits glowplug on time if the system is over 16 volts to prevent damage to the GPs.
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Hotshot
Joined: Jan 2008
Posts: 13,144
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From: Rochdale MA
But the meaning is there. I changed it out. Use symbols instead please.
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Elder User
Joined: Oct 2004
Posts: 916
Likes: 0
From: Hazelton,BC Canada
they are indeed motocraft batteries, im not sure how old, im not the original owner, but for the last 100k or so ive owned it I havent touched it....I did a makeshift load test type thing and with they key on and light and everything else on in the truck after a few minutes it was at 12.06 and had started at like 12.2 or something, I dont think they are weak
Logistics Pro
Joined: Mar 2002
Posts: 3,881
Likes: 84
From: Wake Forest, NC
Did the dash say something different at the time? If it is showing 14 volts on your hand held meter then the charging system is ok voltage wise.
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Elder User
Joined: Oct 2004
Posts: 916
Likes: 0
From: Hazelton,BC Canada
ok I dunno whats up with this thing, it has to be the alternator like my batteries are fine. once the guage started to read high i hopped out and checke the alternator and its charging the same as wh the battery reads for voltage.....so??
