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

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
  1. Home
  2. Questions
  3. After alternator is replaced, battery light still comes on

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Speedometer and Odometer stopped working.

The speedometer on your Mustang is electronically controlled. The speedometer is powered on the light green with yellow stripe wire from the #8 fuse in the dash panel fuse box. The grey/black and the green/orange wires go to the vehicle...

Q: My girlfriend accidentally poured about 5 quarts of water into my engine oil and drove the car 30 plus miles home from work

Hi there, thanks for writing in about your 1995 Honda Civic. There is an old saying about oil and water mixing - and for internal combustion engines, it typically ends up in broken parts. The extra volume of liquid inside...

Q: Wierd rpm spike when coasting in vehicle.

Your car has an automatic transmission and will automatically downshift as the speed of the vehicle slows down. This spike in RPM's is just the downward gear spinning the motor up slightly as it downshifts. Nothing to worry about as...

Related articles

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...