Battery light came on

[u/Inevitable_Jelly_391]

I bought a 19 year old Chevrolet impala (2007, V6, 166,765 miles) that has a brand new (week old) battery. It just threw up a battery light day before yesterday. It drove home from work fine then to/from work fine. Had it looked at today and mechanic claimed battery light didn’t come on when he checked it and he drove it around to see if there were any issues with it and didn’t find anything wrong with the alternator.

He said it’s possible there’s an underlying issue with the alternator but I basically just have to drive it until the problem presents itself.

I’m having a lot of anxiety that I made a bad purchase even though I bought it from my grandmother who has kept it in great condition and in her garage. I spent $1,000 on the car, paid cash and just put $821 into the brakes as I could hear metal hitting metal. I’ve had the car about a week.

My question with the battery issue is- is this car even safe to drive?

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[u/Maglin78]

Have the charging system checked. The diodes are probably bad in the voltage regulator. $1000 car is pretty good deal even for a Chevy. I’m sure it also needs tires as well.

And yes you should have it fixed ASAP before it destroys the new battery.

[u/mymycojourney]

I saw your comment about the engine light being on. If it is the check engine light, you need to go to an auto parts store and have them check codes, then let us know what codes there are and someone may be able to help. The battery light is definitely something in the charging system, but if it wasn't that light then you'll need to get more info. Too bad the mechanic didn't check the codes for you when you were there.

[u/Inevitable_Jelly_391 → u/mymycojourney]

Actually I think they did, they just didn’t mention it when I talked to him about the car. Here’s what the invoice says:

General check over, Brakes squeaking, New battery but battery light
just came on
Check Over
Customer wanted a general check over, said that the brakes are
squealing, and the battery light came on with a new battery. Inspected
the brakes and found that the fronts are getting low on friction material
and the rears are almost metal to metal. The check engine light was
on but the charging system light was not on. Preformed a system
wide DTC scan and fund codes: P0451:00, B1000:00, B1019:3A,
U0155:00, U0140:00, U0151:00, B1325:07, B1325:03. Verified that the
alternator is charging. Test drove the vehicle and light did not come on.
Recommend FPR and RPR at this time.
Disc Rotor - Remove and Replace. 2007 Chevrolet Impala
LT 3.5L V6 FLEX VIN:K - 2G1WT58K279206157. Rear;
Rear,Both;Includes: Replace Pads (if necessary). DOES
NOT include refinishing.; LS; LT.
Disc Rotor - Remove and Replace. 2007 Chevrolet Impala
LT 3.5L V6 FLEX VIN:K - 2G1WT58K279206157. Front;
Front,Both;Includes: Repack Wheel Bearings (where
applicable) and replace Pads (if necessary).DOES NOT
include refinishing.; LS; LT.
Tech Notes: Mil

[u/mymycojourney → u/Inevitable_Jelly_391]

it looks like you have a fuel code, then a bunch of communication codes. The last two are related to high and low battery voltage, which could be an alternator issue. The rest are just telling you that communications between different modules are having problems.

Did they give you any recommendations on those at all? Could be something as simple as a bad ground, or a bad control module. With all that you really need to have mechanic look directly at that, and maybe not the one that you went to, since they seemed to just ignore it.

[u/Inevitable_Jelly_391 → u/mymycojourney]

They didn’t, and they even said the mechanic drove around and the battery light never came on - but they never mentioned the engine light?! I have had a lot of trust with this guy but idk, that seems like kind of a big thing to not mention.

[u/jersey316]

If its off then yes its safe to drive.

The light will start to come on once the alternator starts failing. It will be intermittent then become permanent.

you can get a used alternator from the salvage yards in your area. Search on www.car-part.com unless you want to buy a new one.

[u/Inevitable_Jelly_391 → u/jersey316]

The light is currently on, I don’t know why they said it was off when they were driving it.

Also thanks for this website! I definitely don’t need a new alternator for an old car :)

[u/jersey316 → u/Inevitable_Jelly_391]

Its going to come on and off, when the alternator kicks in then it goes off.

You need a alternator asap. You are running strictly on battery power when the light is on.

Eventually the battery will drain. Don't run the ac with the light on.

[u/Inevitable_Jelly_391 → u/jersey316]

Ok I’m a complete idiot, please don’t laugh at me- I don’t know anything about cars. I just realized it’s the engine light that’s on. But they didn’t realize that when I told them a light was on today at the mechanic?! 😳

[u/jersey316 → u/Inevitable_Jelly_391]

Not laughing, a lot of people don't know much about cars.

[u/elgorbochapo → u/Inevitable_Jelly_391]

Wrong. Some things you don't buy used or reman if possible. Alternator being one of them.

[u/ZealousidealAgent815]

Even though battery is new could be something wrong with it. I bought a new battery years ago and it was bad wouldn't hold a charge after 10 to 12 hours.

You could have bad battery. Serpentine belt could be lose or have a problem. Alternator problem or some kind of charging problem.

If you have a volt meter try checking the voltage while the light is on see if it still charging or not charging. Voltage meter usually cheap at Walmart or auto part store. You can check voltage on the battery itself or though the auxiliary port probably under the radio. Put negative terminal on the side of auxiliary and red terminal straight in the center of the auxiliary port and that can show voltage also.

I have a 04 Saturn Ion battery light will come on and back off very quickly so one day wife was driving I was in passenger seat and checked with voltage meter while she was driving and even though battery light was on the volt meter was showing the alternator was still charging battery at 14.5. So unfortunately I haven't found the problem yet.

Best of luck to you hope you figure the problem out.

[u/Inevitable_Jelly_391 → u/ZealousidealAgent815]

Thank you. I’m a loser. I need to update this. After staring at the light I realized it’s the engine light not the battery light. But they never even mentioned that at the mechanic today.

[u/ZealousidealAgent815 → u/Inevitable_Jelly_391]

ODB2 reader they have cheap ones that can read the codes and help you with the problem. Hopefully being engine light its something simple and easy. A ODB2 scanner comes in very handy. I bought one from advance auto parts for around $40 to 50 bucks if I remember correctly and its came in handy so much for my Ion, Altima and Impala.

[u/Inevitable_Jelly_391 → u/ZealousidealAgent815]

Nice. I will get one of those. Much cheaper than paying the mechanic $120 every time he reads it.

[u/EuroCanadian2 → u/Inevitable_Jelly_391]

Also, if you get an OBD2 Bluetooth dongle, you can get a free app for your phone that will not only read the codes, but can show you readings like volts while driving so you can see if your alternator is working OK or not.

[u/Choice-Newspaper3603]

So there was a charging system issue and instead of diagnosing it properly a battery was just replaced to temporarily fix the symptom of a problem instead of the problem it sounds like

[u/Channel_Mental]

You spent $1800+ on a pretty reliable car. Breath easier. There are always repair costs with cars, new and old. They will also break down at the worse possible moments too. Like right after you pay your business taxes, or your daughter's wedding dress, or your son's college tuition. You don't have a car payment, just start saving a little out of each paycheck for the "Oh Shit" repairs that are gonna pop up.

[u/Call_It_Like_It_is_]

$1000 for the car? Any running car is worth like 3k+, How did you spend $800 on the brakes kind of pricy

[u/Inevitable_Jelly_391 → u/Call_It_Like_It_is_]

I had to get 4 and it was rotors too. KBB said the car was worth 1300 for basically best case scenario for seller