Check the ignition coil for mechanical damage; Check the housing for hairline cracks and sealant leaks. The voltage from a battery is only 12 volts. If no spark is present at the end of the spark plug wire, the air/fuel mixture cannot ignite. If there is a spark, then the ignition coil is not the problem. Results. Disconnect a spark wire from a spark plug (or the coil wire from the distributor cap). Take all necessary safety precautions. If you have an ohm meter, you can check the primary and secondary resistance of the coil. The test you'll be doing is an on car test done with the ignition coil in action. Ignition Coil Test -No Spark No Start Tests (Ford 4.9L, 5.0L, 5.8L), IGNITION COIL TEST 1: Testing For Spark With A Spark Tester, IGNITION COIL TEST 2: Testing For Spark Directly On Coil's Tower, IGNITION COIL TEST 3: Verifying Ignition Coil Is Getting 12 Volts, IGNITION COIL TEST 4: Verifying The Switching Signal With A Test Light, Cómo Probar La Bobina De Encendido (Ford 4.9L, 5.0L, 5.8L). Ford  |   Turn off the engine and ensure the ignition is off. It should be within the range indicated in your service manual. Do not use a regular spark plug instead of a spark tester to test for spark. Use a flashlight or an area with good lighting to perform a visual inspection of the spark plug wires and the cap on top of them, called the boot. Disclaimer. The coil consists of two windings of wire, the primary and the secondary. However, you should have some experience working with car engines before attempting to deal with a coil wire. 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  |   TIP 1: The ignition coil test, I'm gonna show you here, is done with the engine cranking and so you've got be careful and stay alert. How? TIP 2: You'll need a helper to help you crank the engine. TEST 1: Testing The Spark Plug Wires For Spark. 4. Do not remove the spark plug wire from the spark plug or the ignition coil while the engine is cranking to test for spark. From this point, the distributor rotor distributes the spark to the cylinders across the spark plug wires. The dwell period on an engine with electronic ignition is controlled by the current-limiting circuit in the amplifier or ECM. If not, the coil is bad. TIP 3: The ignition coil is not the only thing that can cause a cranks but does not start condition, when it fails. Crack the engine and check for a good spark at the spark tester. All Rights Reserved. Look for physical damage to the wires or boots, such as cuts and scorch marks. 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. She has been published in "Mezzo Magazine" and Diet Spotlight, as well as various online magazines. If the previous test shows no fault, test the primary winding of the coil. Use the Waveform Buffer, Zoom and Measurements tools to examine your waveform. Ferrara studied biology and emergency medical technology at the University of Nebraska and Southeast Community College. 5. You'll need a spark tester, a multimeter, a 12 volt test light, and a helper (to assist you in cranking the engine). Attach the probes to the outer 12V pole and the center pole. Chrysler  |   Measuring ignition coil resistance was once a popular test method. Testing the coil wire is an excellent way to avoid problems down the road. The function of this component is to provide voltage to the ignition control module and ignition coil. Testing the Coil or Armature Step 1 : Clip one end of the spark tester (service part number 19368) to the ignition cable and the other grounded to … The profile ignition pickup (PIP) sensor, which is what Ford calls the crank sensor, gets power from the ICM and as the engine cranks it starts to generate a crankshaft position signal (called the PIP signal). Jeep  |   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. 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. Open your hood and unplug all four wire pin connectors on the coil pack. If necessary, remove any plastic covers that may be covering the ignition coils. Terms of Use Have a second person start the car. Testing these circuits can be accomplished in several different ways. Your purchase helps support my work in bringing you real diagnostic testing information to help you solve the problem! You can use a flat head screwdriver in place of the spark plug to do the bench test. There are two kinds of test available to test your ignition coil, and they are, spark plug test and bench test. An exposed screw or even the negative post on your battery will work fine. This PIP signal is then sent to and received by the ignition control module (ICM). Spark plug wires have become nearly non-existent on many modern vehicles. Check to see if the reading is within the specs listed in your service manual for the secondary winding. TEST 2: Testing For Spark Directly On The Distributor Cap. Note. 2. Bench Test (Coil Wire is Uninstalled) Step 1 Connect your ohmmeter or multimeter to the primary studs of the coil. To test for spark: 1. The 12-volt pole is the spot where the power comes into your coil. 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. Hold the spark plug with insulated pliers and insert it into the coil wire. These will be a line of wires coming out of the cylinder head and attached at the other end to the distributor or ignition coils. Historically, the supply voltage was present as soon as the ignition … Operation and testing coil over plug ignition (4 wire) - Toyota/Lexus Print This case study is perfect for anyone interested in the working details of Toyota/Lexus coil over plug ignition system, and the very similar three-wire designs used by many other manufacturers. It’s important to keep an eye on your spark plug wires to avoid subsequent engine issues. After finishing all these processes, ensure to reconnect your vehicle’s electrical connectors and … Honda  |   Tools  |   When you look at the coil, the primary studs will be sticking out the top and look something like two bolts or poles. Keep both feet on the ground to prevent electrical shock. The resistance should measure around .5 to 1.5 Ohms. Check the electrical wiring and plug connections for damage and oxidation. Replace any faulty coil after testing all the ignition coils. You can choose to do one of these tests or both, just depends on your preferences. A few tests will tell you if the coil is doing its job. The primaryreceives 12 volts from the motorcycle and allows voltage to build; transferring voltage to the secondary winding where voltage is increased to thousands of volts and released through the spark plug wires to the spark plug. Check the electrics using a multimeter or oscilloscope. One goes into the module and the other establishes a connection to the primary resistor and coil. © 2011-2020 Abraham Torres-Arredondo Though its precise location may vary from vehicle to vehicle, generally, it is located near the fender or bolted to a bracket fairly close to the distributor. As I've already mentioned, the type of Coil on Plug ignition coil that we'll be testing has two wires in its connector. This test is for a 4-wire COP with a feedback signal to the ECU. I suggest that you keep him or her outside the vehicle till you need him (or her) to crank the engine. Do not touch the metal. The secondaryof the coil is the area/towers where the spark plug wires plugin. Power is supplied to the ignition coil thru' the wire labeled with the number 2.; The profile ignition pickup (PIP) sensor, which is what Ford calls the crank sensor, gets power from the ICM and as the engine cranks it starts to generate a crankshaft position signal (called the PIP signal). These are usually located right on the engine, either bolted directly to the spark plugs or mounted remotely somewhere on top of the engine. Step 5: Test the secondary circuit of the ignition coil. Connect the ohmmeter to the secondary winding. Again the meter should read about 12 volts. Look for a blue spark from the plug. TEST 3: Testing For Spark Directly On The Ignition Coil. The time between these points is called either the dwell period or the coil's saturation time. As an Amazon Associate, I may earn a small commission from qualifying purchases from the Amazon product links from this website. If a spark is present, the problem is probably in the distributor cap, rotor or spark plug wires. The ignition system has two wires attached to the switch’s run terminal. Turn the vehicle off and open the hood. 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. First measure the resistance between the primary wire that comes from the CDI box and the ground or ground wire. Start your diagnostic from TEST 1, do not skip around from test to test unless instructed to … Check the primary windings for continuity and resistance. If you have already replaced the ignition coil or the tests in this tutorial show that it's good, the following tutorial may be of help: This may seem like a no brainer because the most obvious symptom of a bad ignition coil is a no start no spark condition, but here are a few other symptoms you'll see along with no spark: The one thing to remember, if you do find out that the ignition coil failed, is that the engine will be flooded with gasoline and this may require that you remove the gasoline fouled spark plugs to dry them out (or your vehicle may still not start). This material may not be reproduced without the author’s consent. Connect the meter between the or CB terminal of the coil and earth, and switch on the ignition. Testing the coil can be done with a multimeter and basic mechanical skill. The testing of these two circuits is done in part while the engine is being cranked. TEST 4: Making Sure The Ignition Coil … If the ignition coil has a ground wire, also loosen and remove this at the point it attaches to the lawnmower chassis. Make sure you hold the plastic portion of the screwdriver. Lay the solid end of the plug against a piece of exposed metal. 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997. Next, you need to reinstall the rest of them on to your vehicle. By closing and then opening the Ground circuit this ignition coil's battery power needs to get to ground. Copyright 2020 Leaf Group Ltd. / Leaf Group Media. Comparing the results to the manufacturer’s specifications is supposed … In this article I'll show you a very simple, easy and highly accurate way to see if the ignition coil on your 4.9L, 5.0L, 5.8L Ford F150 (or E150, Bronco, Crown Victoria, Grand Marquis, etc) is fried and causing your vehicle to NOT START or not the cause of the problem. A spark plug needs thousands of volts to have enough energy to turn your engine over. Enclosed units will have a diagram pointing out the primary studs. Do not lean on the fender or against the frame of your car when performing a bench test. Step 3: Disconnect the wiring harness for the ignition coils. First, be sure to have the ignition turned off and the coil disconnected from the ignition. It all starts when you turn the key and start cranking the engine and in a nutshell, this is what happens: In the next page we'll jump right into the first ignition coil test. You won't need any expensive testing equipment to follow the simple step-by-step testing instructions presented here. The process of testing the ignition coil of a leaf blower. Other components can fail and provoke a no start. But before you do any test, it is important to take certain precautions. Refer to the article Fuse Box Informationfor fuse locations. Step 4) If the final result of these wires is not between the indicated numbers then it shows that the ignition coil is bad. Live. Writing since 1999, Darla Ferrara is an award-winning author who specializes in health, diet, fitness and computer technology. Isolate and de-energize the coil. The ignition control module (ICM) and the ignition coil get power (12 Volts). The ignition coil wire sits in the ignition distributor of your car and transforms the battery’s voltage to the voltage needed to stimulate your spark plugs. If you're looking for the resistance test of the primary and secondary circuits, this article will not help you (in my opinion, the primary/secondary resistance test is a complete waste of time and life that does not work around 99% of the time to diagnose a bad ignition coil). It will be marked with a + sign, or it might only be indicated by a number. Using An LED Light To Test The Coil-On-Plug. Crank the engine and watch for spark. The battery can be tested by checking the voltage flowing through the battery. Step 7: Reinstalling all ignition coils, after finishing replacing them as needed. One can further analyze the results by using machines that can test the coils under pressure. The ignition control module (ICM) and the ignition coil get power (12 Volts). Connect your multimeter to the positive terminal or pin of your coil, and to the high output terminal that goes to the spark plug. Watch the next video for a testing example. There are many ways of testing the ignition coil of a leaf blower. 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. Remove the retaining nuts and all the wires attached to the side terminals on the coil as well. Your helper should stay outside the vehicle and away from the ignition switch before and after you set up the test. The PCM will still activate the fuel injectors. Make note of the reading on the ohmmeter. The action of switching ON and OFF the primary voltage (ignition coil's battery power) is referred to as the. Power is supplied to the ignition coil thru' the wire labeled with the. If your plug wires and caps check out, you can now test your ignition coil. Knowing a little practical working theory will answer a lot of questions that the article doesn't answer. What Tools Do I Need To Test The Ignition System? GM  |   Attach the spark tester to the distributor end of the coil wire. Remove all wires connected to the coil, then unbolt it from the engine. 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. Remove the distributor cap and wedge the contact-breaker points open with a piece of plastic or card. By this time, the fuel injection computer is also injecting fuel into the engine, which the spark will ignite, thus the engine starts! Anything below that number proves a deficient coil. 3. Step 2: Locate the ignition coil, or coils, on your vehicle. 7-Wire Distributor Connector Pin Out. Do NOT follow this link or you will be banned from the site! Connect your ohmmeter or multimeter to the primary studs of the coil. 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. Once the ignition coil gets this switching signal, it starts to spark away and as you're already aware, this spark gets delivered to the center of the distributor cap by a high tension wire. Step 4 Place the test leads from the ohmmeter on the side terminals, one on each side. You can find this tutorial in Spanish here: Cómo Probar La Bobina De Encendido (Ford 4.9L, 5.0L, 5.8L) (at: autotecnico-online.com). If you receive a nice, bright spark, your coil is fine. A faulty coil wire will keep your car from starting when you need it. While testing your ignition coils, it’s a good idea to inspect the spark plugs and wires, too. Testing a coil-on-plug (COP) type ignition coil is similar to testing other ignition coils. The primary resistance is measured with the probes on the positive and the negative terminals of the coil. What this means in plain English is that the ignition module interrupts the ignition coil's battery power ON and then OFF. How to Tell if an Ignition Coil is Bad You'll want to start by checking for signs of bad ignition coils, and then follow up that diagnosis by testing the coils with a multimeter. 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 coil is probably the easiest thing to check and therefore the first thing to check when embarking upon ignition system troubleshooting. When you look at the coil, the primary studs will be sticking out the top and look something like two bolts or poles. The only tool you’ll need is a digital multimeter to measure resistance. Remove your spark plug wires from the spark plugs. Open the hood to locate the ignition coil. When the ICM gets the PIP signal, it starts to switch the ignition coil ON and OFF by interrupting the ignition coil's primary voltage. As with most types of vehicular maintenance, you'll want to begin the test with the vehicle in park and with the engine off. To locate the primary and secondary terminals, consult your vehicle repair manual, if necessary. The procedure involves using a digital multimeter (set to ohms) to check the resistance of the primary and secondary windings inside the coil. No spark indicates a bad coil. This will serve as a ground. Insert a spark tester into the wire and attach the tester to ground. Remove the fuel pump fuse. Remove one spark plug using a spark plug socket. If spark is consistently present, the problem most likely lies with the spark plug… How To Test Ignition Switch: The Procedure. Step 3 Touch the red lead on the ohm meter to the spark plug connection and touch the black lead to the armature on the ignition coil. The primary is the area on the Harley Davidson ignition coil where the wires from the motorcycle’s harness are connected. 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With car engines before attempting to deal with a piece of exposed metal coil wire Ltd. / leaf Ltd.! Specs listed in your service manual for the secondary your purchase helps support my work bringing...