Turn off the engine and ensure the ignition is off. When you look at the coil, the primary studs will be sticking out the top and look something like two bolts or poles. © 2011-2020 Abraham Torres-Arredondo Live. She has been published in "Mezzo Magazine" and Diet Spotlight, as well as various online magazines. If you have an ohm meter, you can check the primary and secondary resistance of the coil. The secondaryof the coil is the area/towers where the spark plug wires plugin. With the introduction of coil-on-plug ignition, there is no long wire that is needed to connect a coil to the spark plug.. On engines that are equipped with a distributor or a remote coil pack, spark plug wires are used to transfer the spark from the coil to the spark plug. 3. Some 4-wire COPs have two ground pins and no feedback signal, these should be tested as a 3-wire COP please see 3-Wire COP Test. Look for physical damage to the wires or boots, such as cuts and scorch marks. Hold this HT wire near a grounding point (or near the connector end of a spark plug), and position the tip of a graphite pencil in between. Isolate and de-energize the coil. Turn the vehicle off and open the hood. GM | Ferrara studied biology and emergency medical technology at the University of Nebraska and Southeast Community College. This test is for a 4-wire COP with a feedback signal to the ECU. How? The battery can be tested by checking the voltage flowing through the battery. By this time, the fuel injection computer is also injecting fuel into the engine, which the spark will ignite, thus the engine starts! First measure the resistance between the primary wire that comes from the CDI box and the ground or ground wire. Check the electrical wiring and plug connections for damage and oxidation. But before you do any test, it is important to take certain precautions. To test the coil's secondary winding, attach the test probes to the outer 12-volt pole on the coil and the center pole (where the main wire goes to the distributor). The process of testing the ignition coil of a leaf blower. TEST 3: Testing For Spark Directly On The Ignition Coil. The function of this component is to provide voltage to the ignition control module and ignition coil. Step 5: Test the secondary circuit of the ignition coil. How To Test Ignition Switch: The Procedure. 1995 Ford F150-F350 PCM Pin Out Chart (4.9L California Only), 1994-1995 Ford F150-F350 PCM Pin Out Chart (4.9L Only), 1992-1993 F150-F350 Fuel Pump Circuit Tests (Ford 4.9L, 5.0L, 5.8L), “When I was born I was so ugly the doctor slapped my mother.”Rodney Dangerfield, Home | It’s important to keep an eye on your spark plug wires to avoid subsequent engine issues. Although the following explanation is not theory heavy or full of big technical words/terms, it will help you to see how the ignition coil works. Check the primary windings for continuity and resistance. Testing the coil can be done with a multimeter and basic mechanical skill. Make note of the reading on the ohmmeter. Again the meter should read about 12 volts. Comparing the results to the manufacturer’s specifications is supposed … It's something that you can do without removing these parts (to replace them and see which one solves the no spark-no start problem) and in this tutorial I'll show you how. Now, and in case you're wondering, finding out if the lack of spark is caused by a bad ignition coil or a bad ignition control module is not hard. When you look at the coil, the primary studs will be sticking out the top and look something like two bolts or poles. Anything below that number proves a deficient coil. If your plug wires and caps check out, you can now test your ignition coil. Connect the meter between the or CB terminal of the coil and earth, and switch on the ignition. If no spark is present at the end of the spark plug wire, the air/fuel mixture cannot ignite. The time between these points is called either the dwell period or the coil's saturation time. The only tool you’ll need is a digital multimeter to measure resistance. Power is supplied to the ignition coil thru' the wire labeled with the. If not, the coil is bad. This will serve as a ground. You can choose to do one of these tests or both, just depends on your preferences. What this means in plain English is that the ignition module interrupts the ignition coil's battery power ON and then OFF. Chrysler | Check the electrics using a multimeter or oscilloscope. Check the ignition coil for mechanical damage; Check the housing for hairline cracks and sealant leaks. Do NOT follow this link or you will be banned from the site! Step 2: Locate the ignition coil, or coils, on your vehicle. Attach the probes to the outer 12V pole and the center pole. Do not lean on the fender or against the frame of your car when performing a bench test. Disclaimer. The coil is probably the easiest thing to check and therefore the first thing to check when embarking upon ignition system troubleshooting. One goes into the module and the other establishes a connection to the primary resistor and coil. You can use a flat head screwdriver in place of the spark plug to do the bench test. Ignition coils take energy from the battery (usually 12 volts) and convert it to a high enough voltage (50,000 volts or more) to create a spark. You won't need any expensive testing equipment to follow the simple step-by-step testing instructions presented here. Remove the retaining nuts and all the wires attached to the side terminals on the coil as well. Remove the distributor cap and wedge the contact-breaker points open with a piece of plastic or card. The action of switching ON and OFF the primary voltage (ignition coil's battery power) is referred to as the. However, you should have some experience working with car engines before attempting to deal with a coil wire. Some older mechanics tend to use the method that involves disconnecting the spark plug wire and holding it against a metal chassis while cracking the engine. Look for a blue spark from the plug. Remove the large wire from the center of the coil by pulling it straight out of the coil. Step 4 Place the test leads from the ohmmeter on the side terminals, one on each side. 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