Alternator Dead or Dying?

[pandapod]

So when i bought my car about 20 months ago, the battery died on me shortly thereafter (I kept it in my garage, didn't register it for a few months, but would start it to show it off and putz around the driveway). Shop replaced it and told me my alternator was also bad and I'd need a new one...remember this was 20 months ago. Fast forward to 3 weeks ago, i notice the car is low on battery for about 3 starts in a row. Finally, it didn't start. Got a jump, immediately took it to Advanced Auto, but they failed to diagnose anything because the car wouldn't start again, and they need that for the test program. I ended up driving about 35 minutes to go watch some football at my friends this same day, and surprisingly the car started up when I went to leave. The car continued to work for 1 whole week before it died on me again. It has since not worked and i've needed a jump every time. Note** not once have i noticed dimmed headlights, failing electronics, or has the car died on me while driving.

Now, yesterday, i finally brought it back into advanced auto. Since the battery was completely dead, they told me to drive it for an hour and bring it back. I did so and the battery was putting out 700 or so CCA, but it should have been 900. Technician states the battery is still working but then we checked the alternator and I was only getting 12.6-12.7 Volts out of the thing while running.

Any idea how i should proceed? I'm terrified of doing the alternator job and may just take it to my shop. Think it is for sure the alternator? I don't necessarily want to believe it at this time, and since i was told the alternator needed replacement 20 months ago but i was able to still drive it without issue, i'm hesitant. The belt is in tack but looks to be quite old.

When i start the car there is a loud whining noise for 2-3 minutes but i've read that is normal. I feel like i heard another loud squeaking noise for the first 1 minute the last time i started it too. If videos would help please let me know and i'll post.

Any advice is appreciated...i've searched but found nothing similar to my issue of alternator putting out 12.6V. Think I could just charge my battery all the way up and it will last for awhile with the alternator in it's current state? Anything i can do to prevent spending the $1,000+ on a new alternator will be cool.

[VinnysS4]

If this isn't your daily driver, i would go buy a new belt (recommend changing the tensioner too), put the battery on a charger for a day, put the car into service position and change the belt. (this should only take 30 minutes or so) after the battery is charged up enough to start the car, throw a digital multimeter onto the batter leads. If it reads 12volts the alternator is probably on its way out or has failed completely. You should get around 14 volts with a healthy alternator. Have you checked all of the fuses? You could always get under the car and pull the signal wire going to the alternator and with the key on check to see if it is getting a turn on signal.

[pandapod]

Just to update on my situation, I wanted to see if I had a drain somewhere so I've been disconnecting my negative battery terminal every time I park. Sure enough it's been starting right up every time. So right now it's on a trickle charger, once i'm at 100% i'll drive until i see the problem again and will report back

[VinnysS4]

harbor freight sells cheapo multimeters for like 5 bucks. you can trace a drain with one of these. Might be less inconvenient lol

[pandapod]

Just wanted to update...i charged my car up all the way (charger read 82% when i disconnected it, which i'm assuming is my max since it took 10 hours to go from 80% to 82% and only 2 hours to go from 30% to 50%) and it's been running with zero issues for about a month. Perhaps the alternator is slightly dying, but just enough so that it works most the time. I'll wait and see when it will die again and update my thread once more!

Thanks everyone for the help, but for now all is good (with the battery)

[jar_311]

I just bought a re-man alternator from rockauto for 150 ish + 40 core charge.

[dolby2thx]

Pandapod....check the manufacture date of the battery. There is normally a small decal with a letter and number. Average life of a battery is 4 to 5 years. If your battery is more than 5 years old replace it. I'm betting that is the problem. Let us know.

[pandapod]

Pandapod....check the manufacture date of the battery. There is normally a small decal with a letter and number. Average life of a battery is 4 to 5 years. If your battery is more than 5 years old replace it. I'm betting that is the problem. Let us know.

Hi dolby, the battery is actually less than two years old and appears to hold a charge. I was hoping it was the battery and i could replace it under warranty, but i feel there is some underlying issue that is causing it to drain quickly or just that the alternator is weak

[VinnysS4]

When i bought my S4, the dealer told me they had just changed the battery because it would die and wouldn't hold a charge. When i went to pick the car up after signing the paperwork, it wouldn't start. The guy swore that it had a new battery and what not. I jumped it, checked the alternator for output (14 volts, checked out). I drove to the gas station and it wouldn't start once again. I drove the car 50 miles home, shut it off and tried to start it... and it started right away. I went and replaced the battery with a new one and i have not had a single issue with it since. The alternator has a sticker on it with a manufacturing date of 2013, so i know it is newer. Go down to autozone. They will load test the battery and the alternator and be able to let you know if they are checking withing spec pretty quickly.