battery light on

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Aug 31, 2011 | 03:21 PM

sparke454

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battery light on

had to rescue my daughter from the side of the road the other night. found out that her battery light had been on for a few days. upon getting the truck home I pulled the battery and started to charge it. Pulled the alternator the next day and had it tested and it checked out good. So i checked the ability of the battery to maintain a charge and it held a pretty decently. so i pulled alternator again and took it to a different store for testing and it checked out good again. re installed alternator and put a new belt on the truck. now when i pull the 3 prong plug on the back the light goes off. any ideas on what it could be?

Aug 31, 2011 | 11:50 PM

Bluegrass 7

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Well it's not an idea but how the light works.
Battery voltage through the ignition switch goes to the lamp.
The lamp gets a ground from the alternator regulator switched on or off to control the lamp's on and off condition.
If the motor is running and the lamp is on, then you pull the plug, naturally the lamp will go off (if) the alternator is 'not' outputting enough to make the regulator open the lamp's ground. You did it by pulling the plug and taking the ground away.
The regulator is faulty if the battery charge voltage is up and in the normal range of 14 volts +/- with the motor running and the lamp is still on.
This is explanation #2. See Buzz44 post below.
Good luck.

Sep 1, 2011 | 06:51 AM

SwOkcOffRoader

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From: okc

Alternators are not load tested at parts stores. So a bad unit can give a false pass on their test machine. The same goes with starter tests.

Sep 1, 2011 | 10:06 AM

Buzz44

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From: colbert washington

Morning just thought Id jump in here and ask another question pertaining to this question as a follow up to my earlier post. The question is are these newer alts rebuildable or is it just best to repalece it? In the day Id just get a new or rebuilt and replace it. Not even sure they make the parts or brushes to do any rebuilding for these.

Sep 1, 2011 | 01:13 PM

cv18sro

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Not sure. On my wifes 02 Escape when the alt when out and I took it off, it was totally sealed, I could not see how to get it apart. I just bought her a new one. The one on my truck still works but at quick glance it does look like it can be taken apart, surely someone has kits for them.