Car Battery Light Still On with New Battery? Check This!

Car dashboard lights should light up momentarily as the car engine starts then go OFF.

If one or more stay lit, for example, the car battery light, then take it as a warning that there is an underlying problem that needs to be fixed.

But what if, after replacing a leaky or an old say was 4+ years battery thinking it is the cause of the fault the car battery light stays on?

Is it advisable to drive the car (now that it has a new battery?

Are there any risks if you do so? And how can you fix the underlying fault that is causing the battery to stay on?

Read on to learn if it is safe to drive the car with a new battery (while the car battery light is still on), the dangers if any, and what you may be able to do to fix the underlying fault.

Is it safe to drive with the battery light on after a new battery?

No, it is not safe for your to drive. The car light staying on is a sign that there is a problem with the car’s charging system since it stays lit even with a new battery installed.

The Dangers of Driving With a Car Battery Light Still On (even with a New Battery)

#1. Car Engine Stall

The car engine can stall as you drive once the battery charge is depleted. If the alternator is not able to charge the car battery properly and supply the car’s electrical system with the necessary power needed to run it then the battery will be drained flat.

#2. Damage to the New Battery

The new battery may also suffer damage from being deeply discharged if the underlying problems – the alternator is not fixed or replaced in time.

Why the Car battery may Stay On even with a New Battery

If the car battery light stays on after a new battery has been installed, you can then proceed to check:

#1. Battery and alternator cables

Inspect the alternator and car battery cable terminals for any sign of corrosion – the yellowish, blueish powder coating that forms on car battery terminals.

Corrosion interferes with the terminal and battery post connection and affects the alternator’s ability to charge the battery properly.

Fix: Remove any corrosion buildup by following the steps below and then apply dielectric grease.

How to Remove Battery Corrosion

Safety: wear a face mask and safety goggles

  • Clean the battery posts and battery terminals with a wire brush or an abrasive like light sandpaper or other to remove rust or any traces of corrosion.

This is where the mask and safety goggles come in handy.

  • Firmly connect the battery clamps to the posts so that they make firm clean contact.
  • Lastly, apply the grease over the battery post and clamp connection, like a protective shield to keep out the moisture and any electrolyte from getting into contact with the clamps.

Also, wiggle the battery cables slightly, checking that they firmly connect and there is no break under the installation.

Either of these issues can stop the car battery from charging properly which causes the car battery light to come on.

Fix: Tighten any cable connections. Consider installing battery shims or battery sleeves on top of loosely fitting battery terminals to make a secure connection.

Lastly, inspect the ground cable running from the negative battery terminal to the car’s chassis. A weakly fixed, corroded or broken ground cable will stop the car battery from charging properly.

Fix: If there are any damaged cables, replace them with cables of the same type and gauge.

#2. Faulty alternator

The alternator may be faulty too. The alternator may not be supplying enough voltage to the car or no voltage at all too.

As a quick test, you can measure the alternator’s output voltage with the car engine running and battery cables still connected to the battery using a digital voltage meter.

With the car engine running, the voltmeter should read between 13.5 – 14.5V DC.

A significantly lower or higher voltage is a sign that there is a fault with the alternator, loose or damaged cabling causing the voltage drops.

You should confirm this by having the alternator tested at a reputable auto repair shop to confirm if it is good or faulty.

You may want to read this post: Car alternator or battery: What to Check (Consider rewriting the title)

How Long it Takes the Car Battery Light to Reset?

Usually, there is no need to reset the car battery light at all.

Once a new battery has been fixed or the underlying fault condition affecting the car’s electrical charging system has been fixed then the car battery light goes off with no additional intervention on your part required.

Final Word

If the car battery light stays on even after a new battery has been installed then it is a sign that there is still a fault with the car’s electrical charging system.

You can check the battery and alternator cables to make sure they are free of any corrosion, are clean, intact, and are firmly connected.

Additionally, measure the car alternator voltage to check if it is still working well. You can also take it for additional testing at an AutoZone to confirm it still works or is faulty.

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