alternator chargeing problems
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alternator chargeing problems
ive got a pretty bad problem here, my battery wont charge for some reason. i have an 86 F-250 4x4 with the 4.9L(300) I6. ive replaced the alternator and the voltage regulator and it still wont charge. im pretty sure its not the battery because ive charged it with my "household" battery charger and it holds a charge no problem and registers as 12 volts on my digital multimeter. the strange thing is, if i remove the cables from the battery it works great and i get full power at around 14-15 volts(wich would indicate that its chargeing). if i test it while its connected to the battery i get around 11 volts and everything is dim and sluggish. eventualy the battery will die if i leave it like this and i wont be able to start it again. why wont my alternator charge when hooked up to the battery???
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From: brooks a.b.
it almost sounds like the alt belt is slipping. it would be unable to charge a battery because it loads the alt down and causes the belt to slip. when you are disconnecting the battery it takes the load off the lat and the belt no longer slips. this is the only thing besides a bad alt i can think of. you may want to have that new alt tested to make sure.
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is it expensive to have an alternator checked? is it possible for me to do a complete check myself? it is possible the belt could be slipping, but its not makeing any squeeling noises. the belt is a bit frayed and has some tiny chunks missing on the underside, but i tightened it good and put some non-slip belt spray on it. its been like this ever since i bought it though, so i cant see the belt just suddenly causeing a sever drop in voltage all at once. it is still turning the alternator, but the problem is that the alternator isnt produceing any voltage at all when connected to the battery.
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From: Virginia
Take the + battery cable off. Put your meter on rx1 ohm scale, and make sure it reads when you touch the meter leads together.
Then take one meter lead and put it on the disconnected battery + cable, and take the other meter lead and put it on the + output lug wire of the alt and see if you have continuity. There is a fusible link in the alt output wire that may be burnt in two.
Then take one meter lead and put it on the disconnected battery + cable, and take the other meter lead and put it on the + output lug wire of the alt and see if you have continuity. There is a fusible link in the alt output wire that may be burnt in two.
