Why is the battery light on but alternator is charging?
Why is the battery light on but alternator is charging?
You Alternator Regulator controls the output via an internal ground inside of the Regulator. If you are actually charging at 15 volts sometimes and it goes on long enough it can ruin a good battery. Also you might do a temp swap a Battery from another Vehicle. Even newest Batteries can have internal defects. Thanks for the advice!
What does the battery light read when the engine is off?
With the engine off, it reads 12.5V, with it at idle, it reads somewhere between 13 and 15V (it has kind of a vague scale). Nonetheless, even with just headlights on, the battery light comes on– and when I test the current with headlights, fog lights, and stereo on, it still reads above 12.5V. What the heck?
How can I tell if my alternator or battery is OK?
As with most electrical issues, if you know the battery or alternator is OK (because you had it tested), then diagnosis comes down to tracing and testing for continuity from one portion of the circuit (s) involved to the next.
Can a 15 volt battery ruin a car?
If you are actually charging at 15 volts sometimes and it goes on long enough it can ruin a good battery. Also you might do a temp swap a Battery from another Vehicle. Even newest Batteries can have internal defects. Thanks for the advice!
Why does my alternator light get brighter when I Rev the engine?
This voltage drop causes the light to light, and also results in the battery charging poorly if at all. Usually when this is the case, the light will be very dim at hiatal and will get brighter as you rev the engine.
When does the alternator turn on the idiot light?
When the engine starts and gets up to a high enough rpm for the alternator to start putting out voltage, there is a diode inside that takes some of the output voltage and featured back to the terminal that goes to the idiot light.
Why is the alternator light dim at hiatal?
Usually when this is the case, the light will be very dim at hiatal and will get brighter as you rev the engine. To diagnose the problem, put the positive wire of your volt meter on the alternator output terminal and the negative wire of your volt meter on the battery plus terminal.
How does an IDJIT light work with an alternator?
The idjit light essentially goes from the alternator output to the battery positive. If all goes well, both terminals are at the same voltage potential and no current flows. If either the battery or alternator are not at the same level, there will be current flow through the light and it will illuminate.
Why is the battery light still on after a battery change?
Replaced battery (under warranty, appeared to have one cell bad) but still doing it. Drove to the parts store, pulled the alternator out in the parking lot (could do it in about 5 minutes by now) and brought it in and tested it while hot, it failed.
Is the battery still on after a new battery?
I chanced it when I needed a new alternator, I got a new alternator from Advance Auto, their Carquest 130 amp one, and it is working fine so far, but has a lifetime warranty. One thing when testing alternators is many times they will test fine for the short test when cold on the test bench, but when hot they won’t charge worth a darn.
Why would a good alternator not charge a battery?
The alternator is powered by several different wiring mechanisms. If a wire is not attached properly, becomes detached or is inadvertently cut, the alternator will not have any power. If the alternator is not getting any power, it cannot turn the pulley and belt mechanism that charges the battery, and the battery will not charge.
How do I know if my battery or alternator is bad?
Signs of a bad alternator. If the above steps reveal that the battery is working, it’s time to take a closer look at the alternator. There are certain signs of a bad alternator to look for: While running the car, note the brightness of the interior lights. If the dashboard gradually dims, the alternator is likely at fault.
What are the signs that an alternator is going bad?
One of the most common symptoms of a failing alternator is flickering, pulsating, or dimmed headlights. If your alternator is beginning to fail it won’t be able to power your headlights effectively.
Can a bad alternator damage a battery?
For one, a bad alternator can kill a battery, even if it was not the battery that was the issue to start with. When the alternator is going bad, the battery picks up the slack of providing electricity to the car’s electrical system.
