Battery charging problems...

[Soon2beBlown]

Well just recently my battery light came on and it was showing a really low voltage reading. I figured the problem was the alternator so I went ahead and bought a new one and swapped it in. I cranked it up and the light was still on and it won't charge. I checked all the wiring to the alternator and the battery and it all looks fine. Anyone got an idea why I am having this problem? Any input is greatly appreciated.

 

[HISSIN50]

what is your static battery voltage? then with the car running?
you can have a bad battery and it wont take the charge from the alternator (bad cell). also check your grounds - no ground means hard to get juice into the battery.
you can take it to the parts store and have them check out the charging system for free.

also, did you have the alternator bench tested before installing it? the last one i did, on a chevy S-10, was bad out of the box. the parts store stuff is not great, and you can get a bad unit.

give more info and i bet the folks in here will have some good answers. good luck.

 

[Soon2beBlown]

The battery voltage was like 12 when it wasnt running then when I started it up it just stayed at 12...while it usually goes up to like 13.xx.

It not the battery either...I've tried using other good ones. It may be a bad alternator...I never checked it before installing but it was brand new.

Anyone have any other suggestions?

 

[Hydrocarbon]

Did the new alt come with a new voltage regulator?

 

[Soon2beBlown]

Yes, the new alt. came assembled with the new voltage regulator

What else could it be? Its really getting annoying having to charge my battery before I go anywhere

 

[HISSIN50]

stop by the parts store and have them test it in the car. then you will know. i have gotten bad new parts before. also make sure all of your connections are tight. i once had a system that would fluctuate between 11.5 and 12.5 volts - loose alt power wire.
good luck.

 

[stangbear427]

It may be a bad alternator...I never checked it before installing but it was brand new.

Anyone have any other suggestions?

Brand new from where? Brand new from AutoZone, Western Auto, NAPA, Advanced Auto, Parts America, etc- isn't brand new, it's (hopefully) just a rebuilt. Brand new from Ford, Stinger, Powermaster, PAPerformance, etc, (2-3x$) is a dependable unit and you get what you pay for. I cannot tell you how many chain store alternators I've had dead out of the box. If you pay under $100 for a "new" alternator, you get what you pay for. Just my $.02 I've also found that almost every bad alt/starter I got from a chain store checked out fine on their diagnostic machines. They don't make money taking things back, you know what I'm sayin'? It may not be free like at the chain stores, but I would suggest you take it to a local starter/alternator/auto-electric shop and have them check it. If it's bad, have them re-zing it for you. It cost me $150 to have my local guy build me a 140A 3G alt with no core, some guys in here have had it done for less. Just having one rebuilt as it is shouldn't be more than $50, and it will more likely be done right. Good luck!

 

[Michael Yount]

Hissin and Stangbear (hi guys) are spot on - quit guessing at it, and take it someplace that can do what's called a "load test" on both the battery and the alternator. Most AutoZone's/PepBoys/Sears will do it for free. As Stangbear said, a good alternator/starter shop can test them too, but I'm finding that there are fewer and fewer of those places around any more. Most of 'em have been put out of business because the AutoZone's of the world are selling mass-manufactured/rebuilt units at much lower cost.