Your vehicle's spark plugs may be the source of the spark that ignites your engine and makes it run; however, the ignition coils provide the power that increases the voltage and gets the spark plugs to produce spark in the first place. Since this component functions like the heart of the ignition and is extremely important for your vehicle's overall function, you need to address even the slightest glitch as soon as possible. An ignition coil is basically comprised of a primary and a secondary coil. When comparing the two, you'll easily notice that the former has fewer windings than the latter. The primary coil is the part that transforms the current coming from the battery into a magnetic field, which then causes current to transfer to the secondary coil where the voltage is then amplified because it has more windings. When this component gets bad, you'll have nothing but troubles on the road, so it would be best to fix it right away. To help you get started with your repairs, here's a brief guide that can help you out.
How to Test for a Bad Ignition Coil
Step 1: To begin the test, disconnect the coil wire from the distributor cap and insert an old spark plug into the wire while laying it on the valve cover.
Step 2: Next, crank the engine while closely observing the spark plug. A blue spark indicates functional ignition coils while a pale spark or the complete lack of a spark can mean a faulty coil.
Step 3: If the spark plug produced a yellow spark or did not produce any spark at all, unclamp the negative cable of your battery and then remove the wires connected to the ignition coil to inspect it for any visible signs of damage such as leaks. A leak or crack in the coil means you need to have it replaced.
Step 4: After that, use an ohmmeter to test the coils. Note that they will have slightly different readings but a zero or infinity reading means it is busted.
How to Replace a Bad Ignition Coil
Step 1: Before you begin, make sure that the engine is cool and that the negative battery cable is disconnected.
Step 2: When everything is set, locate the ignition coils under the hood.the location may vary depending on the vehicle you own. Also, note that you may also need to remove several components to access the coils freely.
Step 3: Once you have full access to the coils, unplug the electrical connectors and spark plug wires.
Step 4: After that, remove the mounting bolts of the coils to be able to remove them from the valve cover.
Step 5: Then, mount the replacement ignition coil to the valve cover and secure it in place using its mounting bolts. Make sure you use the right amount of torque to avoid damaging the component. And after that, reconnect the other components that you took out earlier and crank the engine to see if it works.