How To Test your Ford Bronco Ignition Coil

How To Test your Ford Bronco Ignition Coil


When you have no spark in your Ford truck, one of the leading causes can be your Ford Bronco Ignition Coil. If your Bronco is having problems starting, one of the first things you should check is the ignition. When you have confirmed that your Bronco isn’t igniting the air fuel mixture in your combustion chamber, the ignition coil is most often the culprit.

Your ignition system is comprised of a HEI style distributor that’s mounted to a gear. This gear is connected mechanically to your engine, and spark is conducted through the cap and rotor assembly. Today I will be showing you how to test your Ford Bronco ignition coil in a 1993 Ford Bronco equipeed with a 5.8 liter engine.

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When your Ford Bronco ignition coil begins to fail, it’s most often noticed through a lack of power. Lack of spark can also contribute to fouled spark plugs and premature catalytic converter failure. When your Bronco isn’t getting enough spark, it will cause an overly rich condition and cause un-burned fuel to flow into your exhaust stream.

Not only will this create an inefficient combustion cycle, but it will lead to poor gas mileage and excessive emissions. It can cause your MIL or Check Engine Light to go on, and cause your truck to fail your emissions or smog test.

how to test a ford bronco ignition coil

To begin our How To guide to testing your ignition, you need to open your hood and locate the coil. This primary coil will have the center ignition wire leading from the top of your distributor.

Testing your Ford Bronco Ignition Coil for Power

Before you begin our How To guide, you’ve got to make sure that there is no spark going to your 5.8 liter engine. You can do this the old fashioned way, by inserting a spark plug into the wire and resting it against your valve cover, or use a spark tester.

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Spark testers like the one shown above can be inserted inline of any HEI ignition, giving you a safe way to test for spark. The light in this tester should illuminate brightly to show that there is enough voltage at the wire.

If you are sure there is no spark at the wire, the next thing you must check is the high tension wire that’s leading from the main ignition coil. Check this wire to make sure that the wire itself is not bad, or that the metal leads have not corroded. This will eliminate the possibility of other ignition components being bad. When you are sure that the ignition coil is the problem, you must use an automotive multimeter to test for power at the coil. Uncertain of what a multimeter is? Check out our handy guide here to learn how to use one to test circuits in your car.

Locate your Bronco ignition coil and find the two pin harness that’s connected to it. There will be two wires coming out of one side of the harness, and a BLACK wire with a WHITE stripe single wire out the other.

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This is PIN A or the wire we will be checking for power at the Ford Bronco Ignition Coil. To do this turn your multimeter to DC voltage and put the black lead on the negative terminal on the battery. Gently probe PIN A with the red lead and check for 12 volts of power here.

If you have power at this wire the next thing you must do is use a 12 volt test light or probe to see if there’s a signal being sent to the Ford Bronco ignition coil. This signal is called the switching signal and it’s being sent from the ignition control module. The wires you will be testing are coming out of PIN B, wire 1 and wire 2.

Keep your hands and clothing clear of your engine, the drive belts and your cooling fan. Now have your helper crank the engine while your 12 volt test light is touching PIN B, with wire 1 and wire 2 coming out of it.

If you see your test light begin to flicker from the signal from your Ford Bronco ignition control module, this means that your ignition coil is bad. Replace your Bronco Ignition Coil to repair your no spark issue. Make sure to shop our online store for your direct fit replacement ignition coil to fix your spark issue.

Have any questions about our How To DIY guide to testing your Bronco Ignition Coil? Leave us a message below and let us know!