Why Car battery light Stays On with a New Battery?

Car battery warning light points to a problem with the charging system. It could as well be that the battery is faulty.

But what if you replace the battery with a brand new one and still the battery light stays ON? Puzzling, isn’t it?

Well, read on to find out why the car battery light may stay ON with a new battery, what it means, and for suggestions on what to check and fix to clear the light.

Why Is the Car Battery Light Still on with a New Battery?

If the car battery light stays ON after a new battery has been fitted in the car, then check the following:

#1. Inspect the battery and alternator wire connections. Check for any signs of corrosion, or damage to the battery and alternator wires.

In some cases, wire connections may appear intact on the outside yet the conductor is damaged under the insulation.

You may have to gently tug at the wire connections such as the ground or alternator plug connections to confirm that this is not the case.

#2. Inspect the alternator belt. Does it show any signs of damage? Is it properly fixed or is it slipping? If not properly fixed because of lack of proper tension or damaged then it may not be able to run well enough to generate the expected voltage hence triggering the battery warning light.

Is the alternator pulley running smoothly or are there any unusual noises? A wobbly or noisy alternator can affect how well the car charging system works and may cause the car battery light to come on.

#3. Faulty Alternator. An alternator that is not able to supply the expected voltage may be at fault.

Perhaps its brushes are worn, it has a damaged diode, has burnt windings, or another fault.

A quick test for a well-functioning alternator is to measure the alternator voltage at the battery when the engine is running. It should be in the range of 13.5 – 14.5.

If lower or higher then there is probably a problem with the alternator. You can also use an <alternator tester>.

You can also take it to a reputable auto repair shop where it can be tested comprehensively.

Is It Dangerous? Should you Ignore It?

You should not ignore the lit battery light. You may get stuck with a flat battery or end up spending more to fix the underlying fault that would have been avoided if you had acted in time.

For example, if the alternator is faulty, it may damage the battery too. So not only do you have to replace the alternator but the battery too.

So, do not ignore the battery warning light, it is a sign that the car’s charging system is not working properly.

How Long Does it take for the Light to Reset?

In most cars, as soon as the underlying fault that was affecting the car’s charging system has been fixed whether it is the wiring, bad battery, or other, the car battery light immediately goes off on its own.

How to Reset the Car Battery Light

There is no other action required on the part of the driver to clear the battery warning light.

Final Word

If the car battery light stays on even after a new battery has been installed, most probably there is still a fault in the charging system that needs to be addressed.

Perhaps it is loose fitting or damaged alternator or battery cables, a damaged or slipping alternator belt or tensioner, or a bad alternator.

Any of these might be the reason why the battery light stays on. Do not hesitate to consult a qualified mechanic to support you on this.

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