Driving to work one morning with the window cracked down, i try to roll it back up, it barely goes, im thinking WTF. Park it and the battery light comes on. check over the voltage over the battery and its barely 12.2. Then just to make sure i jump the car and remove the negative terminal from the battery...car dies. OK off to kragen to buy a new alt. I install it and it reads 14 volts across the battery, I think everything is fine....until the next day.

comming home from work, i try to roll up the windows, and it struggles, i think nothing of it. I get a call to go play some golf, go to start up the car, and yep its dead. I jump it and test the voltage, its only reading 12.7 wtf.

Can someone help me out here, its a day old alternator and it doesnt seem to be charging my battery. When i jump it and remove the negative terminal it dies as well.

I was told to check the alternator with a light thing (hook one end up to a negative while the car is on ACC, and touch the other end to the alt ground) if it lights up your alt is fine.

Any clues?

 

how old of a battery? maybe the battery cant hold the charge or maybe you have something draining your battery inside the car such as a light or whatever. you can do the ohms test and see how much she is pulling, it should be about .02- .06 i believe someone correct me if im wrong but i knw i had the same issue and mine was pulling .4ohms the whole time & never dropped off.

 

if the battery was the problem, would the voltage across the battery when the car is running still be under 13?

 

thats a super vague and innacurate way of testing alternator output. This shouldn't be a complicated issue. I doubt this is your issue, but many times the distributor poors oil on the alternator frying the poor guy. Other times connections are loose. there is also a chance your battery is comletely dead, has a bad cell and could be causing your alternator to full field, basically overwork and burn up.

 

thanks guys, I just switched everything out, and it seems to be running fine, i'll try and rig up an alternator shield so no oil drips on it.