Ok i have a 1986 cavalier convertible, and the alternator charged when i first hookup a freshly charged battery, at 14 volts, but after about 2 hours, it stops charging at 14 and drops to about 12 volts, and drops. and stays that way for a week or so till the battery dies completely. i've replaced the alternator, belt is tight, replaced the wiring, anyone have any ideas?
Al
Sounds like the battery won't keep a full charge.
Maybe you have another bad alternator. The convertible is known for this problem.
Sounds like either a bad ground the or a short that's pulling all the juice from the system. Did they load test the alternator off the car?
battery is good, holds a charge in any other vehicle. the alternator test's bad on car but good off car.
Al
yeah, they load test it with thier machine...was putting out 14.7 volts.
Al
i'll run another ground wire for it just for fun, see what happens.
Al
Try running another wire directly from the charging post of the alt to the positive post on the battery in the event that the fusible link is toast....I've seen it happen before....
JC
>but why would it charge for a little bit, then quit? if the fusible link was toated it wouldn't do anything ever....unless it just got broken and occasionally touch's.
Al
Have you actually hooked a voltmeter to it to see if you're really getting
14vdc outta it? It may be that the fully charged battery (which can actually hold somewhere around 13vdc) may be showing 14 on the gauge for the first couple of hours, and then as the battery drains, the needle falls......Try the jumper and see what happens....
JC
completely.
checked it out, it's deader than crap..... :-/ i think the alternator was going bad, then finally took the big dump the other day, when the car started to die completely.
Al
Have something to add? Share your thoughts — no account required.
Ask the community — no account required