How to Test a Car Lightbulb with a Multimeter

How to Test a Car Lightbulb with a Multimeter?

I hate when my headlight stops working. It is a real bother to get to it, let alone change it.

I am usually thinking of taking my car to the mechanic in such instances, but then I realised that it is just a light bulb.

Yes, it is difficult to get to it, but once you do get to it, you can use a multimeter to check the lightbulb and replace it if it is really broken. 

If the problem is in the car, well, then you will need to take the car to the mechanic.

Luckily, the problem is very often only in the bulb and you will now find out how to test the car headlight bulbs with a multimeter.

car light

This sort of thing can really help you save time and money.

If you see that the bulb has black marks on the inside you can be sure that it is broken. If, however, the bulb does not show any sign of damage, be it from overloading or cracking, then things can get a bit more trickier and you need to test it with a multimeter.

Before we begin, it is very useful to know that some cars come equipped with a set of spare lightbulbs in the trunk. If your car didin’t come equipped with the set of spare bulbs in the trunk then you are going to have to buy new ones.

New car headlight bulbs can cost from eight to one hundred and fifty dollars, depending on the type of the car, the output socket and so on.


It’s very important to do this correctly.

For this sort of thing, you don’t need an expensive multimeter since the probability of electrical discharge is literally zero.

You just need to relax and have fun while doing this.

Here’s the deal

  • Remove the plastic or glass cover on your car to get to the bulb.
  • Unscrew the bulb out of the socket and take the multimeter.
  • Set the multimeter to continuity mode. You can easily verify that you have correctly set the multimeter to continuity mode by pressing the probes together. If the multimeter is set on continuity mode, it will produce a beeping sound.
  • Place black probe to the negative side of the bulb.
  • Take the red probe and for a moment press it against the positive pole.
  • If the bulb is in working condition, the multimeter will beep.
  • If the bulb is broken the multimeter will not beep because no continuity exists.

So, that’s it.

You too can now save at least one hundred dollars that you would give to the mechanic and for buying new bulbs by doing this yourself.

And this isn’t just limited to cars.

is my multimeter working

What Else Can I Do?

You can test household bulbs that have stopped working just like this. 

Although some differences in the output exist, the basic principles remain the same and, trust me, all that it takes for you to know how to do this on other bulbs is to see them. You will immediately recognize what part of the multimeter to place where. 

But that’s not all.

You can use the continuity mode to test Christmas lights, for example. If the half of your christmas lights suddenly stop functioning, use a multimeter. Set the multimeter on a continuity mode and locate the broken light. All you need to do then is to replace the broken light.

The basic principles apply to every household item from a microwave oven to bulbs. When you suspect that something is broken you need to check the continuity. The basic principle of checking the continuity is to pinpoint the positive and negative poles and to place the probes on them.

Regardless of the size and function of the device that you are testing, If the device is not broken or burnt up, continuity exists. If continuity exists the multimeter will produce a light or sound signal, depending on your model of the multimeter.

I hope that you won’t just read this, I hope that you will apply all of the advice here and realise just how simple and fun it is to save money by doing something fun that you have always wanted to do, only to discover that it is so easy.

After you test this out, you will question yourself why didn’t you start doing this sooner.

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