How to Test a Coil Pack with a Multimeter (Step-by-Step Guide)

A coil pack is something that takes energy from a car battery and converts it to a high voltage. This is used to create a spark that starts up the car. A general problem that peoples face is when a coil pack is weak or faulty, it causes problems like poor performance, low fuel economy, and engine misfires. Therefore, the best prevention is to know how to test the ignition coil pack with a Multimeter so you will be able to avoid all problems related to the car ignition coils.

In general, to check the coil pack with a Multimeter check the default resistance for the primary and secondary windings. Connect the multimeter’s negative and positive leads to the correct terminals to test these. After comparing the resistance with the default resistance in the vehicle manual you will see whether your ignition coil pack needs replacement.

We will go through more detail in our article below.

Why Test a Coil Pack?

car engine coil pack

We check the coil pack because it is an important mechanism in the engine and like all the other parts it has a unique duty which is to provide power to the individual spark plugs. This in turn generates fire to the plug and creates heat on the cylinder.

How to Test a Coil Pack with a Multimeter

There are different vehicle models and each one of them has its ignition coil pack located at different parts of the vehicle which is why the essential first step is finding the coil pack. Below is a step–by–step guide which will show you how to find a coil pack, how to test the coil pack with a Multimeter, and, how to reinstall your ignition coil pack.

Finding the Coil Pack

  • When looking for a coil pack you first have to find the plug position or battery in your engine.
  • You can notice that the same color wire connects the plugs and all you have to do is follow the wire.
  • After reaching the end of these wires, you will see a single part where all the four or six or eight wires connect depending on the total counts of cylinders of the engine. That part where they meet is primarily the so-called ignition coil pack.
  • In case you are still unable to locate your ignition coil pack then the best thing to do is to search the internet for your particular model or your vehicle manual and you will be able to check the coil pack location of your engine.

Testing the Coil Pack

  • The first step when you want to test coil pack is to remove all the initial connections from the spark plugs and also remove the car ignition coils from the engine.
  • After removing all the connections, you will then need to use a Multimeter. Because the resistance of the ignition coils is an issue you will need to set the Multimeter on the 10-ohms reading section.
  • The next thing you need to do is to place one of the ports of the Multimeter on the middle connector of the primary coil of the primary ignition coil pack. Immediately you do this, the Multimeter should read a number less than 2 ohms. If this is indeed true then the primary coil result is good.
  • You now need to measure the resistance of the secondary ignition coil pack which you will do by setting the ohmmeter at the 20K (20,000) ohms section and placing one port at one coil and another port at another coil. A car ignition coil pack should bear a reading between 6,000 ohms to 30,000 ohms.

Reinstalling a Coil Pack

  • The first thing when reinstalling a coil pack is to move the ignition coil pack in the engine deck and then tighten all three or four bolts with the right size of socket or ratchet.
  • The next thing is to reconnect the plug wire with all the ports of the car ignition coil pack. This connection is to be done based on the name or number.
  • You should then connect the battery wire with the primary coil port which is distinguishable from plug ports.
  • The final step is to connect the negative port of the battery which you have disconnected at the starting point of this whole process.

Necessary Things to Remember while Testing the Coil Pack

multimeter test coil pack

There are a few certain things that you should remember whenever you’re testing or checking the coil pack of your vehicle. They are important guidelines that can’t be avoided because they not only keep you safe but they ensure actions you take don’t cause any bodily harm to you. These necessary things are as follows:

Wire Gloves

When planning to test the coil pack of your vehicle, you need to make sure you are wearing rubber hand gloves. Wearing rubber hand gloves will protect you from different potential hazards that might occur. For instance, these gloves will protect your hands from the harmful chemical found in the engine and car battery. (1)

Gloves will also protect your hands from rust which is found around different parts of the engine. The last and most important thing rubber gloves protect you from is an electrical shock which could happen because you will be working with spark plugs and batteries that may create electric power.

Ensuring the Engine is off

People tend to leave the engine on when working on their cars but the truth is when you leave your engine on, there is a huge possibility of receiving an electric shock by the spark plug when you’re trying to test the coil pack of your vehicle.

The spark plugs generate burnable gas which burns and also transfers electricity so you need to make sure the engine is off before starting any work.

You should also make sure to work in a well–ventilated environment and in any case whereby electrolytes get on your clothing or body, you should promptly neutralize it with a mixture of baking soda and water. (2)

Wrapping Up

Something else you should remember is to always connect all the ignition coil pack ports to the right wire and a good way of doing so is to label them by number or give a specific sign to avoid all forms of mistake.

I would also like to advise you to take precautions before starting your work. An exception taken from the necessary safety guidelines might lead to an unwanted situation. You should make sure to read and follow these sets of instructions to get the best results from testing your ignition coil pack.  Double-check to make sure you didn’t miss any steps.

With this tutorial, you now know exactly how to test a coil pack with a Multimeter and I hope you’ve enjoyed it.

Check below other multimeter learning guides;

(1) harmful chemical –
(2) mixture of baking soda and water –

About Sam Orlovsky

b1d87d2ee85af3e51479df87928bdc88?s=90&d=mm&r=gI realized early on carpentry was a huge passion for me and I’ve stayed in the industry for over 20 years now. This gives me a unique ability to really be able to tell you what the best tools and recommendations are. I’m not only a carpenter but I also like machinery and anything to do with electrics. One of my career paths starting off was as an apprentice electrician so I also have a lot of experience with electrical products and anything related.