Battery Light On, Possibly Alternator?
Thread Starter
Joined: Apr 2017
Posts: 38
Likes: 0
From: NY
Battery Light On, Possibly Alternator?
Hoping someone can reassure me that I am replacing the right part.
While driving the car on the highway this past sunday the battery light came on. Once i had arrived at my location a couple minutes later i noticed it had went off. Didnt think too much of it but kept an eye out the rest of the day and no issues. Yesterday I take the car out and the battery light was illuminated at idle. A small rev to the car would make it go off and then would re-illuminate back at idle and over 3k rpms. I took it to autozone to have the battery and alternator tested and wouldnt you know it at that point the light was off and both tested fine. Today i drive the car to a few errands and the last stop the car wont start. I get a jump start and head home where the battery completely drained and the car died about 10ft from the driveway. Normally i would say alternator but know our cars are quirky and could be something else. The battery is about 8 months old, The terminals have no corrosion and are connected fine, battery and alternator tested ok yesterday but something is obviously not right since today i had to get a jump and then died, and the belt shows no signs of wear or oil on it. Is the alternator bad or should i be looking at the voltage regulator as the culprit?
While driving the car on the highway this past sunday the battery light came on. Once i had arrived at my location a couple minutes later i noticed it had went off. Didnt think too much of it but kept an eye out the rest of the day and no issues. Yesterday I take the car out and the battery light was illuminated at idle. A small rev to the car would make it go off and then would re-illuminate back at idle and over 3k rpms. I took it to autozone to have the battery and alternator tested and wouldnt you know it at that point the light was off and both tested fine. Today i drive the car to a few errands and the last stop the car wont start. I get a jump start and head home where the battery completely drained and the car died about 10ft from the driveway. Normally i would say alternator but know our cars are quirky and could be something else. The battery is about 8 months old, The terminals have no corrosion and are connected fine, battery and alternator tested ok yesterday but something is obviously not right since today i had to get a jump and then died, and the belt shows no signs of wear or oil on it. Is the alternator bad or should i be looking at the voltage regulator as the culprit?
Senior Member
Joined: Sep 2015
Posts: 1,465
Likes: 4
From: Knoxville
Re: Battery Light On, Possibly Alternator?
The regulator is built into the back (removable plate) of the alternator. Also check were the ground attaches to the body at the fender. The cables have built up corrosion under the plastic covering before, leading to ground strap replacement being a cure. Let us know what you do an try. 
Senior Member
Joined: May 2008
Posts: 10,434
Likes: 144
From: Cincinnati ( Delhi )
Re: Battery Light On, Possibly Alternator?
I have seen batteries with intermittent problems. Start and test good one minute, fail the next, sit a while and test good again.
I would say check the grounds at the fender, but if it jumps fine, then I doubt that would be an issue.
Please report back when you find the problem. James
I would say check the grounds at the fender, but if it jumps fine, then I doubt that would be an issue.
Please report back when you find the problem. James
Thread Starter
Joined: Apr 2017
Posts: 38
Likes: 0
From: NY
Re: Battery Light On, Possibly Alternator?
Well after checking out the ground and them being OK I replaced the alternator and problem fixed! Kind of funny how it tested fine then next day it's toast