2000 5.7L Battery Light

chevrolet
tahoe

#1

My 2000 Chevy Tahoe Battery light came on. Replaced the battery and it stays on. I understand it could be the alternator but the ODD thing is that I just got my car back from having the upper / lower ball joints replaced. Could wiring have been knocked loose? This truck is a work horse. I’ve had it forever very few repairs and over 300k miles. I’ve never replaced the alternator.


#2

Proper diagnosis for a proper cure. There are many possibilities, my first guesses would be a worn serpentine belt, bad ground connection, bad terminal, bad alternator, but these all can be diagnosed.


#3

thank you. i am considering taking it to the chevy dealer since they know these best. thoughts?


#4

Yes it could very well be the alternator. This is the problem with the pictures on indicator lights. It has a battery on it so people assume it’s a battery problem. An oil can for an oil pressure problem, to me an oil can would mean low oil level. And we do. Hear of people getting the oil can symbol checking the oil, level reads fine and drive on till engine destruction. Pictorial symbols suck. I just think the indicators could be better. Sorry for the rant.


#5

Did a shop replace the battery? did you ask them to check the charging system?


#6

It is not necessary to take it to a dealer. There are plenty of good, independent auto shops out there that can diagnose and repair your Tahoe for less money than the dealer. Stay away from the chain stores like Pep Boys. Ask your friends and look online for reviews. Don’t be surprised if the alternator needs replacing. 300K is a nice lifespan for an alternator.


#7

No i did not have it at the shop. the battery light was on for a couple days and then it wouldn’t start in my garage. My son came over and took it out and we got a replacement at the auto part store but the light is still on so I decided not to drive it until I figure out where to go/ what to do. I can take it some place and have the charging system checked and alternator inspected. thanks for your help and feedback


#8

You are right about that! Battery light and we thought battery. We don’t know much about cars here! :frowning:


#9

Ok thanks for the feedback! I appreciate it.


#10

PS. my son said it doesn’t sound right at idle to him…idk what that means


#11

Could be a rattle from the alternator. Could also be a rattle from an idler pulley - the spring loaded pulley that keeps the belt tight. The mechanic should check those (you might have 2) while he’s got the belt off for the alternator change. Might want to replace the belt, too, if it has been a lot of miles since that’s been done.


#12

thank you so much. I’ve got an appt tomorrow morning. I owe you. Jotted down notes for tomorrow to ask questions.


#13

One thing is certain, if the alternator isn’t working you’ll soon find out. The engine can only run for a certain amount of time before it will stall out if the alternator isn’t working. 30 minutes to an hour probably.

Shops usually offer a comprehensive charge system and battery test, that’s probably the way to go here.

There’s an off-chance the problem isn’t either one. Sometimes the car designers will turn on the battery light if something else important has actually failed and needs immediate attention, like the brakes. It’s a fail-safe if the warning light bulb burns out on the dash. Unlikely, but should be considered.

My guess, it is p[probably related to the recent service, so take it back there for an evaluation.


#14

The battery light is tripped when the voltage being provided by the alternator is low. It says battery but it’s really alternator. It used to say “alt” but maybe the had a sale on battery labels or something. At any rate when the light goes on, check the alternator output first. I suppose they might have bumped a wire or forgot to put the ground wire back on but for some reason stuff happens after being in a shop.