ok so im having some problems with my charging system on my car. Im totaly stumped i put a good charged battery in an start my car it runs. i drive it an then it starts to die. i took my alt to autozone they checked it said itwas perfectly fine charging an everything. so i thought it was the battery. but i stuck it in my other car drove the car for 30 mins shut it off. when back about 20 later started up first try ran perfect an the gauge said 14volts. so that puts the battery out of the check list. but im stumped unless my alternators bad an still says it charging. could there be anything else a fuse i know everything is grounded i need to check my enigne ground off the battery but im 100.000% sure its good. any one please. ps what dones Bump mean i see alot of people use that

 

I'm having the same problem as you. I'll be installing my second new alternator tomorrow (first one was a dud) and I'll see if that works. Sometimes alternators will test as good when they are bad, so it might be worth trying a new one.

"Bump" is just something people post if they want to bump their thread back to the top of the page, so that people are more likely to see it.

 

yea well that makes sence. yea me to im on my second one now i had one but i guess when i put in my new motor i shorted out my main an my warning lights all stayed on. an eveyone said alternator so i tryed it an the one i got was junk. so i took it back an got a new on an its now charging an my lights are still on. i think about it an shoulda keep my first one atleast my battery stayed charged with it.

 

Autozone alternators are notoriously bad, and typically run at about 50% of them bad out of the box.

It is not uncommon to have someone try 2 or 3 different alternators from autozone before they find one that actually works. Autozone alternators typically are rebuilt (which means they only replace the broken parts and clean it) instead of remanufactured (all wear parts replaced) or new. And as you have seen their QC if very very poor.

That said, the alternator should be charging at 14.4 volts when the car is running. If the voltage is less than 13.5 volts then the battery will not charge. And if the voltage is less than 12.6 volts, then the car is running on battery power and there is not enough voltage coming out of the alt to even run the car. If it is not suppling sufficent voltage, then either the alt belt is mis-adjusted and slipping or the alt is not hooked up correctly or the alt is bad. Pretty cut and dry.

And bumps are forbidden in this section. Here in the 2nd gen tech section we feel everyone's question is just as important as the next, so no one should ever be bumping a thread.

 

Yea well i was be a cheap *** an went to the junk yard an pulled one of a 2nd gen i just had it checked by two stores advanced auto an autozone an both said good so im think something else. battery is fine cause i used it to drive my other car an it stayed perfect whole time i did see in my fuse under the fase my engine fuse was a7.5 insted of a 15 so i changed that would that be anything to do with it

 

good question Iwanna know

 

Fuse value wouldn't matter, unless it was blown.

I wouldn't trust autozone to test an alt any more than I would trust an alt from them.

Is the voltage dropping under 13.5 volts?

Is the voltage dropping under 12.6 volts?

Yes to either of those points to a bad alt, loose connections to the alt, or loose belts.

 

Got a new alternator, fixed my problem. Just FYI, my alternator tested "good" with one of those machines, but when I did the tests from the FSM it failed on two of them.

 

Where do you suggest to get new alternators from?

 

im pretty sure it was my battery cause it took a crap on me yesterday in my other car. so i put a new on in an its charging. but when i start it it start then the car dies an if i keep cranking it its like there no spark after it dies

 

honestly, i would check all of your wiring. just run thru all of it and check for any exposed wires. i had the same problem, but it was because i had an exposed wire and it was shorting out. after taping that up and making sure everything was good it worked fine...

im glad i read this tho, because i have an alternator from autozone and that pos doesnt charge more than like 12 volts and barely holds a charge when i have the windshield wipers and defrost going.

 

lol i beat u to it i did friday night an everything was good. so the next morning i went out to try it with the battery. tryed to start my other car nothing so i put the charger it started ran. charged to 14 shut it off. came back out about 3 hours later it was dead. so i just got a new battery seems to be good now.