How To Test an Ignition Coil in a Vehicle?

The ignition coil is an important a part of your vehicle. Also known as spark coil, this induction coil is usually a part of the ignition system of your car. This means, when you start the car, it capabilities the batterys low voltage and converts it into a high voltage that is enough to create a spark in the spark plugs. In turn, this will ignite the gas and start the car.

The main job of the ignition coil and the system as a whole is usually to increase the 12 volts of cars battery into the very high voltage, so it can ignite the gas mixture present inside the combustion chamber. The role of the coil is usually to produce this high voltage that is right enough to power the car. As you can see, the ignition coil plays an important role in the entire functioning of the automobile.

So, it is important that this coil works well as you are unable to even start the car without it! It is a good idea to test this ignition coil if your car does not start for any reason.

Lets right now see how you can test.

You will find two kinds of test available to test your ignition coil, and they are, spark plug test and bench test. You can choose to do one of these checks or both, just depends on your preferences. But before you are doing any test, it is important to take particular precautions.


Screening the engine of your car is more dangerous than you may think. Make sure you have the right security equipment such as safety goggles to prevent any untoward accident. Also, make sure you are not wearing any loose clothing and your hair is tied back well. These precautions are necessary because your engine generates electricity, and it is also better to be safe than sorry!

Spark Plug Test

After youve taken all the precautions, you are able to do the spark plug test.

spark plug

As a first step, remove the wire from your plug. If you are not sure which wire or if you are doing this test for the first time, keep the cars manual with you. Identify the right wire based on instructions from your manual and remove it.

Next, remove the spark plug with the help of a spark plug socket. Never attempt to do it with bare hands.

After taking out the spark plug, attach the plug cable back. Contain the plug cable using protected pliers, and invite the bare end from the spark plug to contact a grounded surface area. such an shown metal area. Consider help from your own partner or another person, and have them to start out the ignition. When the main element is fired up, you should visit a shiny blue spark by the end from the spark plug.

Obviously, in the event that you dont start to see the coil, this means your ignition coil isn’t working and it requires to be changed.

One drawback with this check is that it’s hard to learn if the ignition coil isn’t working therefore well. Quite simply, you may visit a spark, nonetheless it could be feeble. As non-technicians, it really is hard to tell apart if the spark was shiny or feeble. That is why the bench check is a far more thorough method of assessment your ignition coil.

Bench Test

This bench check is focused on the principal and supplementary windings of your vehicle. Before starting, keep carefully the car manual handy and take note of the standard reading for every of the two windings. Generally, the principal winding could have a reading of 0.75 to 0.81 ohms as the supplementary winding could have a value of 10,000 to 11,000 ohms. Verify your manual for the precise values.

ignition coil

Now, to check on this resistance, connect the ohmmeter to the exterior poles of the principal winding. For the supplementary winding, attach one end to either of the poles and the additional end to a central high pressure terminal. Then check the ideals.

As you can see, this test is definitely more thorough as it gives the precise state of the ignition coil. Actually if the readings are a little off from your manual, replace the ignition coil as these off readings could indicate that it is weak.

Thus, these are the two way to check whether the ignition coil within your engine is definitely working fine. When your checks show that you have to replace them or if you feel the coil is definitely weak and needs to be replaced, get in touch with a reputed auto repair shop to do this job for you.

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