Battery/Charging Problem

[land5150]

I have a 92 camry, 4cyl. I replaced the alternator about 4 months ago. I have had no problems until today. The battery light came on, and car did eventually die. It did jump off fine, tried to get to a shop, but it just wouldn't make it.

On a hunch, I pulled the battey and had it checked. It was bad and I replaced it. After driving for awhile the battery light came on again. The strange part is that the light will go off if I am running 2000 rpm or more. If I stop at a light, the battery light will come on again.

Anyone have any ideas? The alternator belt and connections seem fine. Any help is appreciated.

[toyboyracer]

YAaaaaarrrrr Matey, I hads the exact SAME problem with me
Frigate the "Blue Pearl" only a few months ago.

On the scurvy alternator there be a small rectangular box held on
by 2 screws 'n it be the regulator n brush unit.

So for a few pieces of eight and undoing 2 screws, yer tub should be
sailing again in less than 10 Fathoms

Aaaaaaarrrrrrrr

[Tercel GTS]

The replacement alternator has gone defective.
Most likely a diode has gone bad, but the possibility exists that the rotor is not making full contact with the brushes.

If you remove the alternator you can open and check yourself using my thread listed in the ultimate stickies in tech section.

[lucanhookup]

mabe the alt fuse has gone out

[Kep]

Lots of the auto parts stores around Houston will check the alternator and battery for free. Maybe there are some in your area. It is a quick check but if the alternator turns up bad then you'll know. If you only got it 4 months ago it may still be under warranty. If it is, changing the alternator is simple.

Kep

[Mike Gerber]

It is most likely your alternator again. The failure rate for rebuilt alternators is fairly high, so this is not uncommon. It should still be under warranty. If you installed it yourself you know it is a 10 minute job to remove it. Do that and take it back to the place you got it from and ask them to check it and if it's defective to give you a new one. If you had it done at a shop, take it back there and have them deal with it.

Mike

[Streetglower]

either your second alternator failed, or you have a voltage drop in the charging system that is reoccuring and shops will mistake it for a faulty alternator. voltage drops tests are used to check for resistance in the circuit caused by loose or corroded connecters, or faulty cables. What I would do is first check the output of the alternator, if it fails, charge the battery, start the car and using a DMM, place the positive lead on the battery and the negative lead on the positive terminal of the alternator and watch the volt reading. SHould not be more then .5V. then check the negative side, place the black lead on the negative post and the positive lead on the alternator case and read the voltage. SHould not be more then .2V. if either is out of spec, check the connections for corrosion or loosness and if those check ok, replace the cables or add another cable of the same length and gauge from the battery to alternator and retest the output. If the output then is within specs, you know the voltage drop was the cause.