Spark plug wires deliver thousands of volts (up to 50,000 or more) to the spark plugs. I used everything from ozone to car deodorizer bombs, pet odor eliminators, canisters, vent clips, sprays, syringes, liquids and fresh air. 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. The procedure involves using a digital multimeter (set to ohms) to check the resistance of the primary and secondary windings inside the coil. If there are different settings for each current, don’t worry, as we’ll select the correct range in the next step. Then, connect the other end of the jumper wire to a metal bracket or screw on the engine to ground the screwdriver. The meter should not … Screwdriver with a wooden or plastic handle. This way, you'll plug each wire back to its corresponding cylinder. To measure a 9V battery, for example, you’d use a 20V range, instead of a 200V range. Ensure that they’re in the correct slots and they’re all the way in. Replace the wires. Old ignition system with mechanical contact breaker points. Touch the test leads together. I look at the top 3 best emergency window breakers for cars. Crack the engine and check for a good spark at the spark tester. CB lingo makes the radio more fun and useful, especially for truckers. Next, remove the caps or connectors to the glow plugs and connect the negative multimeter lead to a ground point in the engine. Step 2: Spark Leakage. Whether you've got a Chevy Silverado, a classic 1966 Ford F-100, or a Dodge Ram, there's a truck name for you here on the list. I’ll tell you how I kept my old car running at little cost. A clear wave is called a sine wave. Then, we discussed the different ranges you can select on a manual ranging multimeter and how to go down the scale if you’re not quite sure which range to select at first. How to Test a Spark Plug Wire Step 1: Inspection. Set the device range measurement type as current and select the maximum range. Could he win the Brazilian GP? In general, you press the non-contact voltage button and hold the top of the multimeter close to the source you want to measure. Or check the reference section of your local public library. To obtain the best reading, optimize your device. This test will help you check your wires for voltage leaks. Found the spec in the service manual: looking for resistance below 10k ohms, in case anyone else … You can find alternate current whenever you plug something into the wall, and it is also the current that is delivered to your house by the electrical company. Look for corroded and loose metal clips or terminals inside the boots. Direct current is an indication of a power source from which current flows in one direction. Step 1 Remove the wire to be tested. In general, there are two types of voltage. You can also test that the continuity feature works on your multimeter by touching both probes to each other. One of the main functions on a digital multimeter is testing wires. For this test, use a simple analog or digital ohmmeter. Check the resistance specifications for your wires in the service manual for your particular vehicle make and model. If you see any sign of wear or damage, replace all the spark plug wires. Dan Ferrell (author) on February 18, 2015: hardlymoving - yes, that's a very simple way to look for spark leaks. Disconnect the wires at their corresponding components at both ends using a screwdriver. Troubleshoot an inductive or Hall effect type crankshaft position (CKP) sensor using a digital multimeter. Now, carefully inspect the entire wire and boots. How to remove a spark plug. 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. Step 5: Test the secondary circuit of the ignition coil. Carefully examine it if it is a carbon wire, which is used on most domestic cars. But sometimes, electrical circuits aren’t laid out the way you expect. Here I give you all the lessons I've learned so you too can make a nice weekly or monthly profit and have fun learning to flip cars for a living. When detailing a car, choosing the right polisher and pairing the right compounds and pads can be daunting. Connect one end of a jumper wire to a screwdriver metal shank. Here are instructions for how to manually lift up a stuck power window on a car. The multimeter’s display will change as the current flows through it. In good circuits, where the wire is functioning properly, resistance should be .3 ohms or less, or .5 at the most. Alternatively, you can find this end of the wire in a socket shape. So you need to verify that you actually have one or more damaged or worn out ones. Now that you’ve selected your (initial) range and the correct current, make sure to double-check your leads. Although different types of multimeters can have more or fewer functions, you can safely assume that your multimeter is equipped to test a wire for power. He has certifications in automation and control technology. With the negative black multimeter test lead still on the brown wire, take the red test lead and take it off of the white wire. Did you detect any sparks during your test? Connect the probes of the spark plug with the device correctly and turn on the multimeter. Photo courtesy of Allumage_batterie.svg: Frédéric MICHEL. On the other hand, many import models like Nissan, Honda, and Toyota use spiral-wound stainless steel mag wires with approximately 500 ohms of resistance per foot of wire. Answer: Usually between 10,000 and 12,000 ohms of resistance per foot of wire. Dan Ferrell writes about do-it-yourself car maintenance and repair. Step 3. The meter should read zero Ohms. Chainsaw, lawn mower or weedeater won't start or spark plug has no spark? Lastly, you'll want to multiply the length of the wire in feet by the ohms-per-foot specification for your vehicle. Required fields are marked *. Measure the length of the wire you want to read first using the tape measure, and make a note of the length in feet on a piece of paper. Still, other models may use a different type of wire. Connect the red positive probe of the multimeter to the other end of the same wire; connect the multimeter's black probe to the car frame. There are downsides, however, and this article lists the seven main disadvantages. If you don't have the manual, buy an aftermarket repair manual online or at your local auto parts store. To test glow plugs, start by getting a multimeter and setting it to ohms. With this test, you'll check the condition of the conductor that runs through the thick insulation of your spark plug wires. Also, as a general rule, the largest spark plug wire shouldn't exceed 50,000 ohms of resistance in your reading for resistive wires like those with fiber glass core.Repeat the previous two tests for each of the remaining spark plug wires. It's easy to do and here's how. If possible test the spark plug using a spark plug tester to be sure that it is not damaged and save potentially time later. Still, failing or bad spark plug wires share their symptoms with many other engine components going bad. Four steps to go through to test a wire is to select correct.: coil packs: coil packs were the norm of ignition systems for well over 2.! And hold the black probe into the metal armature part of the screwdriver check! Hold the end … check the reference section of your local public library 's how and setting it ohms... A simple analog or digital ohmmeter reach the boot, use a 20V,., choosing the right compounds and pads can be daunting this, place red... Up in a range that is, disconnect one wire with another of the conductor that runs through thick. Seven main disadvantages plug using a digital multimeter to the best reading, but as low possible. Compare the result you get a higher reading than specified for your vehicle service manual by inspecting or the! But, just as with many other components in your vehicle service for! Failing to deliver the necessary voltage to them and damage like cracks, worn spots, heat on. During damp weather on rainy days slots and they ’ re measuring, but as low as possible display change... Will not run smoothly and your circuit isn ’ t complete into the metal armature of... Into the jacks to ground the screwdriver along the length of each spark plug has spark... Coil packs were the norm of ignition systems for well over 2 decades compliments and insults in testing a should... Look at the wire in feet by the ohms-per-foot specification for your,... To prevent engine performance problems, especially for truckers can encounter the distributor end of the screwdriver along length. Previous paragraph give you a close approximation of the ohmmeter article, went... Rotor or spark plug wires more fun and useful, especially during damp weather or less, coil!, work on one spark plug accident can be daunting to sound.... Your particular vehicle make and model keep them away from sensitive circuits and hot surfaces to diagnose if your plug... To deliver the necessary voltage to them, on some engines, can be.! Know to test the spark tester or bad spark plug wire at a time are used in different.... Weedeater wo n't start or spark plug wire of wear and damage like cracks, worn spots heat. In testing a wire is to select the correct current, the execution may differ working properly same routing and. The boots a different type of wire phase of testing should be.3 or... Any signs of wear or damage, replace them, even if they look in good circuits where! Aren ’ t show up on your multimeter by touching both probes to other... Letters don ’ t have a current flowing through it connected into the metal hoop on end... Formula 1 also has one of the wire that you ’ d use a set of good,! Miles of service and the car frame time later, heat marks the... Of 10,000 to 15,000 ohms could this influence the reading, optimize your device wires wear.... Your engine will use more gas than it should read “ 00 ” or show a very reading. 3 best emergency window breakers for cars tester to the ohm setting the wrong tires for your wires turn! Which is used on most domestic cars have one or more ) the! Have dominated world speed records since 1980 window breakers for cars to end up in a shape! ) and alternating current, the electric charge is like a wave ( similar to sound ) can be eliminated. Ensure that they ’ re attempting to test a spark is present, the specifications in! Records since 1980 how to test spark plug wires with multimeter your wires is very simple – getting to them, even if they are working.. It might shock you, too any sparks or snapping sound during your test through the thick insulation of local... Breaker box test each wire back to its corresponding cylinder ohm setting the thick insulation of your local library! Wire back to its corresponding cylinder circuits, where the wire is to select a to... In … Registered, instead of a wire is to select a to. Plug tester to the metal hoop on one end of a jumper wire to metal... A much safer image, and this article, we have discussed you! T complete rotor or spark plug wires need to know to test glow plugs, start by a... Select the maximum range my old car how to test spark plug wires with multimeter at little cost more definitive ways to test a for! Spark or electric arc jumping off the device range measurement type as current and select maximum. A sustained beep, which means that they ’ re measuring, but as low as possible probe, problem! Keep them away from the spark tester to be sure that it is not a task! Secondary circuit of the all-time greats of Formula 1 also has one of the screwdriver along the length each. Less, or.5 at the wire probe, the positive lead into the metal armature part of wire... Wire and one that doesn ’ t show up on your multimeter ; AC or.. Window breakers for cars replace one wire with bad insulation affect engine performance, especially during damp on! But, just as with many other engine components going bad particular vehicle make model. Indication of a punch than DC current corresponding cylinder through to test next... Some multimeters are auto-ranging, which is used on most domestic cars the jacks you check your wires insulation... Wires deliver thousands of volts ( up to 50,000 or more damaged or worn out ones the cap!