How to Test Kohler Ignition Coil with Multimeter: The Ultimate Guide for Beginners

Are you experiencing starting issues with your Kohler engine? A faulty ignition coil could be the culprit. This critical component delivers high voltage to the spark plugs, igniting the fuel mixture and enabling your engine to run. Knowing how to test a Kohler ignition coil with a multimeter can save you time and money by allowing you to diagnose the problem yourself.

Understanding the Ignition Coil

The ignition coil is a transformer that steps up the low voltage from your engine’s electrical system to the high voltage required to generate a spark at the spark plugs. It consists of a primary winding, a secondary winding, and a core. When the ignition system sends a signal to the coil, the primary winding creates a magnetic field. This magnetic field collapses when the signal is interrupted, inducing a high voltage in the secondary winding. This high voltage is then sent to the spark plug, creating a spark that ignites the fuel.

Symptoms of a Faulty Ignition Coil

A faulty ignition coil can manifest in various ways. Here are some common symptoms:

• Difficulty Starting: The engine may crank but fail to start or start intermittently.
• Misfiring: The engine may run rough, backfire, or experience a loss of power.
• No Spark: If the ignition coil is completely faulty, there will be no spark at the spark plugs.

Tools and Materials You’ll Need

Before diving into the testing process, ensure you have the following tools and materials:

• Multimeter: A digital multimeter (DMM) is essential for testing the ignition coil’s resistance and voltage.
• Spark Plug Wrench: To remove and inspect the spark plugs.
• Safety Glasses: Always wear safety glasses when working with electrical components.
• Gloves: Protect your hands from potential electrical shocks.
• Kohler Engine Manual: Refer to the manual for specific wiring diagrams and testing procedures for your particular model.

Testing the Ignition Coil: A Step-by-Step Guide

Now that you have the necessary tools, let’s walk through the process of testing the Kohler ignition coil with a multimeter:

1. Disconnect the Ignition Coil

• Safety First: Before disconnecting any electrical components, ensure the engine is off and the ignition key is in the “off” position.
• Locate the Ignition Coil: Consult your Kohler engine manual to identify the location of the ignition coil. It is typically mounted near the spark plugs or the engine’s cylinder head.
• Disconnect the Wires: Carefully disconnect the wire(s) leading to the ignition coil. Note the position of each wire to ensure you reconnect them correctly later.

2. Test the Primary Winding Resistance

• Set the Multimeter: Set your multimeter to the ohms (Ω) range.
• Connect the Leads: Touch the positive (+) lead of the multimeter to one terminal of the ignition coil and the negative (-) lead to the other terminal.
• Read the Resistance: The multimeter will display the resistance of the primary winding. Consult your Kohler engine manual for the specified resistance range for your model. If the reading is outside the specified range, the primary winding may be faulty.

3. Test the Secondary Winding Resistance

• Set the Multimeter: Keep the multimeter set to the ohms (Ω) range.
• Connect the Leads: Connect one lead of the multimeter to the high-voltage terminal of the ignition coil (the terminal with the wire leading to the spark plug). Connect the other lead to the ground terminal (typically a metal bracket or the engine block).
• Read the Resistance: The multimeter will display the resistance of the secondary winding. Again, refer to your Kohler engine manual for the specified resistance range for your model. A reading outside this range indicates a potential issue with the secondary winding.

4. Check for Continuity

• Set the Multimeter: Set your multimeter to the continuity test mode.
• Connect the Leads: Connect one lead of the multimeter to the high-voltage terminal of the ignition coil and the other lead to the ground terminal.
• Check for Continuity: If the multimeter beeps, it indicates that there is continuity between the high-voltage terminal and the ground terminal. This is a good sign that the coil is not completely faulty.

5. Test for Spark

• Inspect the Spark Plugs: Remove the spark plugs from the engine and inspect them for signs of wear or damage.
• Connect the Spark Plug Wire: Connect one end of a spark plug wire to the high-voltage terminal of the ignition coil. Hold the other end of the spark plug wire near a grounded metal surface (like the engine block).
• Crank the Engine: Have someone crank the engine while you observe the spark plug wire. You should see a bright blue spark jumping across the gap. If there is no spark, the ignition coil is likely faulty.

Troubleshooting and Replacing the Ignition Coil

If you find any of the tests above indicate a faulty ignition coil, you’ll need to replace it. Here’s a general guide:
1. Locate the Replacement Coil: Identify the correct ignition coil for your Kohler engine model. You can find replacement coils at your local auto parts store or online retailers.
2. Disconnect the Old Coil: Carefully disconnect the wires from the old ignition coil, making note of their positions.
3. Install the New Coil: Connect the wires to the new ignition coil in the same positions as the old coil. Ensure the wires are securely connected.
4. Recheck the Connections: Double-check all connections and ensure that the ignition coil is securely mounted.
5. Start the Engine: Start the engine and test it to ensure it is running smoothly.

Beyond the Ignition Coil: Other Potential Causes

While a faulty ignition coil is a common cause of starting problems, other issues could be responsible. Consider these possibilities:

• Spark Plugs: Worn or fouled spark plugs can prevent proper ignition. Inspect and replace them if necessary.
• Ignition Wires: Damaged or worn ignition wires can disrupt the spark delivery. Inspect and replace them if necessary.
• Battery: A weak or dead battery can prevent the ignition system from functioning correctly. Check the battery voltage and charge it or replace it if needed.
• Fuel System: Problems with the fuel pump, fuel filter, or carburetor can prevent the engine from receiving fuel. Inspect and troubleshoot these components if necessary.

Final Thoughts: Keeping Your Kohler Engine Running Smoothly

Testing your Kohler ignition coil with a multimeter is a valuable skill for anyone who owns a Kohler engine. By understanding the process and troubleshooting potential problems, you can save time and money while ensuring your engine runs smoothly. Remember to always prioritize safety and consult your Kohler engine manual for specific instructions and specifications.

What You Need to Know

Q: How often should I test my ignition coil?
A: It’s a good idea to test your ignition coil periodically, especially if you experience any starting or running issues. You can also test it as part of a regular engine maintenance routine.
Q: Can I use a test light instead of a multimeter?
A: While a test light can be used to check for continuity, it’s not as accurate as a multimeter for testing resistance and voltage. A multimeter is the preferred tool for comprehensive ignition coil testing.
Q: What are some signs that my ignition coil is going bad?
A: As mentioned earlier, common signs include difficulty starting, misfiring, and a lack of spark. If you notice any of these symptoms, it’s a good idea to test the ignition coil to determine if it’s the source of the problem.
Q: What is the lifespan of a typical ignition coil?
A: Ignition coils typically have a lifespan of several years. However, factors such as operating conditions and environmental exposure can affect their longevity. If you suspect your coil is nearing the end of its life, it’s a good idea to test it and replace it if necessary.