How to Test a Car Ignition Coil

Ignition coils are essential components of your car, and if they’re not functioning properly, your engine won’t start. Unfortunately, there’s no one definitive way to test an ignition coil, as each car is different. That said, there are a few basic steps you can take to ensure that your coil is in good working order.

What is a car ignition coil?

A car ignition coil is a device that helps to start a car. It is made up of several coils of wire and is situated directly beneath the key in the ignition switch. When the key is turned, the current through the coil causes it to heat up, which in turn starts the engine.

How to test a car ignition coil

If your car won’t start, or if the engine is sputtering and not turning over, you may need to test your car’s ignition coil. This guide will show you how to do it.

First, check the battery to make sure it’s fully charged. Next, turn off the car’s engine by pressing the key in the “on” position and then turning it to the “off” position. Next, disconnect the negative battery cable.

Now, remove the spark plugs from the cylinders one at a time and hold them up so that they’re facing out of the cylinder head. Next, connect one end of a 10-foot length of electrical wire to each spark plug and connect the other end of the wire to a ground lug on the engine block (or another sturdy terminal).

Start up the engine and wait until it reaches operating temperature (about 700 degrees F). Then, use a voltmeter to measure the voltage across each spark plug while the engine is running. If one or more of them has a reading below 12 volts, that indicates that there’s probably a problem with that cylinder’s ignition coil.

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What to do if the coil is bad

If you’re having trouble starting your car, it’s likely that the ignition coil is bad. Testing the coil is a simple and affordable way to determine if this is the case.

To test the ignition coil, remove the battery cable and check for sparks when you touch the metal terminals with a wire. If there are no sparks, the coil is most likely bad and needs to be replaced. If there are sparks, the coil may be good but needs to be tested again later in the year, after it has been run under less extreme conditions.

Testing an ignition coil isn’t a guarantee that it’s bad, but it’s a great way to rule out problems before they become expensive and time-consuming problems.

Conclusion

Testing a car ignition coil can be a necessary step in troubleshooting a no start or poor engine response. By doing this, you can determine if the problem is with the coil itself or something more serious. Here are four steps to follow to test your car’s ignition coil:

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