Why a multimeter is not the best way to test an ignition coil. Turn the lawn mower's ignition switch on and pull the rope to spin the flywheel. I do have a blue-white spark that I could not see in sunlight but taking it indoors made it visible. When it comes to testing ignition coils, the first thing we all want to do is grab our multimeters to check the resistance. Remove any covers that may be obstructing access to the glow plugs, and use the flashlight for additional illumination if necessary. by Eduardo Ruelas on August 01, 2016 Share Tweet Pin. One of the coil’s terminals should be shown leading to the spark plug. Serviceable Spark Plug Resistance. Try to start the chain saw. That method will only tell if there is something seriously wrong with the coil (aka if it's dead). Even if you find a bad coil, simply replacing it is not the whole repair, because like so many other parts of a vehicle, COP ignition coils don’t really die, they’re murdered. Plug the probe into the multimeter’s pot. For new plugs, we recommend 4000 ohms as the maximum acceptable value. Furthermore, measuring anything over 10 amps could blow a fuse or destroy the multimeter as well. If a spark jumps from a plug wire to the test light at any point, this is an indication that the insulation has broken down, and the spark plug wire should be replaced. Using a meter lead, attach the spark plug wire terminal to each coil. most of the times the spark plug or the coil pack would be bad and these are not expensive when compared to a fuel injector. Otherwise you could blow the fuse that’s inside of the multimeter. Testing spark plug wires with a multimeter (ohms) ... Ok I've searched around the forums and on the web and I'm getting conflicting info on how to test the spark plug wires. On the box titled ‘ Applies To ’ on the right column, you'll find a complete list of Nissan and Infiniti models that this test article applies to. Damage to the vehicle and severe injury may result. This a pretty straight forward test, but one that has to be done with the HEI spark tester. As the name suggests this tests the spark plug, or more accurately it tests whether there is an electrical current capable of generating a spark. TEST 1: Testing For Spark. Test the coil with a multimeter.Disconnect the coil pack's electrical connector then remove the coil pack from your car's engine using a wrench. You must consider attaching the spark plug tester to the wires of the coil of your chainsaw, instead of connecting the spark plug back to the wires. Set the ohmmeter/multimeter to 200 ohms range then turn it on. Individual coils for each cylinder that attach with a spark plug wire, similar to the LS motors used on Chevy and GMC trucks, can also follow this method. Spark plug: be sure it is the correct type, heat range, and thread depth, replace with a new plug or know working plug for testing Breaker point(s) and condenser: replace rather than testing, these parts commonly fail due to age and wear, they are VERY common for causing "no spark" If your test constantly flickers when you start the engine, you can continue and make sure that your plugs are … With this test, you'll check the condition of the conductor that runs through the thick insulation of your spark plug wires. You will be able to see the wire spark in low light conditions. A standard multimeter has three parts – a screen, a selection knob, and two, three, or more ports. Each foot of a wire should have a resistance of 10,000 to 15,000 ohms. Plug caps may be cracked, which can cause corrosion or an open circuit. Test the 24-pin motherboard power connector: Connect the negative probe on the multimeter (black) to any ground wired pin and connect the positive probe (red) to the first power line you want to test. Shop Aircraft Spark Plugs Step 2: Check your ICM spark plugs (ignition module) for power. If the loss of contribution moves with the coil, the ignition coil is faulty. An absence of spark will require replacement of the ignition coil. I know there are other more definitive ways to test the wires but I wanted to just do a quick ohm test. A multimeter won't test for good spark. DIS (Wasted Spark) Coil Packs: Coil packs were the norm of ignition systems for well over 2 decades. To test the cap, you will need to remove it. There are a number of ways to test your car's ignition coil without removing it, but the most definitive test is one that removes the coil and tests it with a multimeter. Most glow plugs are installed in the cylinder heads and will have a heavy gauge wire, similar to a regular spark plug wire, attached to them. To verify whether the coil is to blame, you’ll want to swap the coil to another cylinder and repeat the power balance test. Step 1 Remove the cowling and fuel tank from the engine by undoing the relevant bolts … Attach the test light to a good engine ground. With the tests in this article, you'll be able to test and diagnose: A BAD power transistor, or a bad ignition coil, or a bad distributor cap, or bad spark plug wires on your Nissan vehicle. The misfires should be less than or equal to 5 in every 1000 if not then you might have to change the coil pack or fuel injector in the particular cylinder. Then set your multimeter to measure ohms(Ω). A higher resistance indicates bad wiring. With the engine running, move the test light along the length of each spark plug wire. I strongly recommend against having the multimeter even touch the spark plug wire! Step 3: Disconnect the glow plug wires. Testing continuity in a wire, current, or fuse is a good idea if you’re installing or repairing any electrical components in an outlet, fuse box, car, or appliance. The easist way to check for spark is to remove the sparkplug, attach the spark plug wire, hold the threads of the plug up … Warning: Make sure that if you’re measuring anything with a current higher than 200mA, you plug the red probe into the 10A port, rather than the 200mA port. How to Test a Spark Plug Ignition Coil If you suspect your car has a faulty spark plug, use a multimeter to test it out in 7 straightforward steps. You simply remove the HT lead and plug the device in-line, so it connects to the end of the HT lead and the base of the spark plug. This is not a standard test done with a multimeter and thus you should use all protective gear including eye cover and electrical gloves. How to Test a Spark Plug Ignition Coil. Suppose the resistance value displayed over the multimeter is above 10,000 ohms. If a spark is present, the ignition coil is working properly. to test ignition coil primary resistance you can probe terminal 1 (-) and 15 (+)..and you should read approx 0.8 ohms. If possible test the spark plug using a spark plug tester to be sure that it is not damaged and save potentially time later. Watch the spark tester or spark plug, looking for a spark between the electrodes of the tester or spark plug. Here are a couple suggestions that'll help you to avoid wasting money and time (by not replacing a good part): Do not use a regular spark plug instead of a dedicated spark tester.