An ignition coil is a vital part of any internal combustion engine that ignites the fuel mixture in the cylinders. If the ignition coil fails, the engine will not start or run properly. Therefore, it is imperative to test the ignition coil regularly to ensure that it is functioning correctly. Using an ohmmeter is a common and effective method to test an ignition coil, and this guide will provide step-by-step instructions on how to do it.
Before you begin testing the ignition coil, ensure that the engine is turned off and cool, and the battery is disconnected. You will need an ohmmeter, also known as a multimeter, to perform the test. An ohmmeter is an electrical instrument used to measure the resistance of a circuit or component. The resistance of the ignition coil should be within a specific range, which varies depending on the type of ignition coil. Refer to the vehicle’s service manual or the ignition coil manufacturer’s specifications for the correct resistance value.
Once you have gathered the necessary tools, locate the ignition coil on the engine. The ignition coil is usually mounted on the engine block or near the distributor. Disconnect the electrical connectors from the ignition coil. Using the ohmmeter, set the dial to the ohms setting. Connect the black lead of the ohmmeter to the negative terminal of the ignition coil and the red lead to the positive terminal. The ohmmeter should display a resistance reading. Compare the reading with the specified range in the service manual or manufacturer’s specifications. If the resistance reading is outside the specified range, the ignition coil is likely faulty and needs to be replaced.
How to Test an Ignition Coil with an Ohmmeter
An ignition coil is a critical component of an internal combustion engine. It converts the vehicle’s battery voltage into thousands of volts, which are then used to create a spark at the spark plugs. A faulty ignition coil can prevent the engine from starting or running properly. Testing an ignition coil with an ohmmeter is an easy way to check its condition.
To test an ignition coil with an ohmmeter, follow these steps:
- Disconnect the negative terminal of the battery.
- Remove the spark plug wires from the spark plugs.
- Set the ohmmeter to the lowest resistance scale.
- Touch one probe of the ohmmeter to the primary terminal of the ignition coil. This is usually the terminal that is connected to the negative terminal of the battery.
- Touch the other probe of the ohmmeter to the secondary terminal of the ignition coil. This is usually the terminal that is connected to the spark plug wires.
- Read the ohmmeter display. The resistance should be between 0.5 and 1.5 ohms.
If the resistance is outside of this range, the ignition coil is likely faulty and should be replaced.
People Also Ask
What are the symptoms of a bad ignition coil?
The symptoms of a bad ignition coil can include:
- Difficulty starting the engine
- Engine misfiring
- Reduced engine power
- Increased fuel consumption
- Check engine light illuminated
How often should an ignition coil be replaced?
Ignition coils typically last for 100,000 miles or more. However, they can fail prematurely if they are subjected to excessive heat or electrical stress.
What is the cost to replace an ignition coil?
The cost to replace an ignition coil varies depending on the make and model of the vehicle. However, it typically costs between $100 and $300.
