Skip the auto shop - Our mechanics make house calls

Q: After alternator is replaced, battery light still comes on

asked by on

Last week while driving, for about 3 seconds the battery light flickered on and then off. The voltmeter jumped up and down between high and low. Two days ago, the battery light appeared again and this time it stayed on. The meter kept low and then started dropping lower and lower. I was thinking that the problem was probably the alternator and as I was trying to get to my house the instruments began to go out. First the tach, then the speedometer, and then the accelerator pedal was unresponsive. I was able to limp for a little while, but it eventually totally quit. After jump-starting the truck, I made it to the mechanic’s shop. They tested the battery and it was fine until the engine was on and then it was only getting 12 volts, not the 13 or 14 that it should have been getting. They reported it was a bad alternator and then replaced it. The truck performed well throughout the next day until the battery light came on again. This time the voltmeter was at the proper place, about 2/3rd way up and approximately 13 or 14 bolts. Later in the evening, the light came on again but only below 1500 RPM and the meter was ⅓ and around 1 volt. I returned to the auto repair shop again and discovered that they had given me a rebuilt alternator - a bad rebuilt one. This time they gave me a brand new alternator. While going home, the light faintly appeared again! The voltmeter is now staying around 12 volts. All of this makes me think that the alternator is not the problem. Can you tell me what “is” the problem and also tell me how to fix it? Thank you

A: Hello. It is possible that the problems tha...

Hello. It is possible that the problems that you have been experiencing with the bad alternators have damaged the battery causing it to be weak. This would make the Battery Light come on. It is also possible that there is a problem with the fusible link or the alternator fuse for the charging system.

I would suggest that you have a certified technician, like one from YourMechanic, test the battery and complete an inspection of the electrical system in order to pinpoint the problem and make the necessary repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car in limp mode, check engine light on

In this case you should have an experienced technician look at the vehicle. Limp mode is usually a term used for a vehicle with an automatic transmission which stays in second gear when certain faults arises. A certified technician, like...

Q: speedometer not working

The vehicle would need to be lifted and the cable checked to see if it is turning. If it is, then the speedometer is bad. If the cable does not turn, then disconnect it from the transmission and see if...

Q: I press the gas pedal but the car isn't getting gas. The engine doesn't rev up.

Good question. I want to go through a few steps with you and hopefully find your problem and save you some time and money. If you find the issue during steps, then ahead and fix that fault and you should...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.