How to Test Ford Coil Pack with Multimeter? Expert Tips and Tricks 2023

Many people ask how to test Ford coil pack with multimeter. Well, to test a Ford coil pack with a multimeter,

“locate the coil pack and disconnect the electrical connector. Set the multimeter to the ohms setting and connect the positive lead to the coil’s center terminal and the negative lead to one of the outer terminals. A good coil will typically show an average resistance. The coil pack functions properly if the resistance values are within the specified range.”

What is a Ford Coil Pack?

A Ford coil pack, also known as an ignition coil pack, is a component of the ignition system in Ford vehicles. It generates the high voltage needed to ignite the air-fuel mixture in the engine’s cylinders. The coil pack consists of multiple individual coils connected to a spark plug.

How to Test Ford Coil Pack with Multimeter

Modern Ford vehicles often use a “coil-on-plug” system, where each cylinder has its own coil pack. This design provides better ignition performance and allows for more precise control of the spark timing.

How to Test Ford Coil Pack with Multimeter? A Step-by-Step Guide

A coil pack is an essential component of the ignition system in a Ford vehicle. It is responsible for delivering the high voltage required to ignite the air-fuel mixture in the engine cylinders. If you suspect your Ford coil pack is faulty, you can perform a simple test using a multimeter.

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This guide will outline how to test Ford coil pack with multimeter. If you are unsure or uncomfortable performing these tests, it is recommended to consult a professional mechanic.

Materials Needed

1. Multimeter (digital or analog)

2. Safety goggles

3. Insulated gloves

4. Electrical tape

5. Pen and paper (for note-taking)

Step 1: Safety Precautions

Before proceeding with any electrical testing, it is crucial to prioritize safety. Put on safety goggles and insulated gloves to protect yourself from potential electrical shocks. Ensure the vehicle’s engine is turned off and the ignition key is removed.

Step 2: Locate the Coil Pack

The coil pack is usually situated on top of the engine, and its appearance may vary depending on the Ford model. Consult your vehicle’s manual or search online to locate the coil pack for your specific Ford model.

Step 3: Disconnect Electrical Connections

Once you have located the coil pack, carefully disconnect all electrical connections. These typically include the primary wiring harness connector and any other connectors attached to the coil pack. Ensure you do not damage the connectors or wires during this process.

Step 4: Set Up the Multimeter

Set your multimeter to the resistance (ohms) mode. If using a digital multimeter, select the appropriate range, usually around 20k ohms. If using an analog multimeter, set it to the lowest resistance range.

Step 5: Test Primary Winding

Identify the primary terminals on the coil pack. These are typically labeled as “B+” and “B-.” With the multimeter probes, touch one probe to the “B+” terminal and the other to the “B-” terminal. Note down the resistance reading displayed on the multimeter.

Step 6: Compare Resistance Reading

Compare the resistance reading obtained in Step 5 with the manufacturer’s specifications. Consult your vehicle’s service manual or search online to find the correct resistance values for your Ford model. If the resistance reading is significantly different from the specified range, it indicates a faulty primary winding.

Step 7: Test Secondary Winding

Locate the secondary terminals on the coil pack, often labeled as “Cyl 1,” “Cyl 2,” and so on. Each terminal corresponds to a specific engine cylinder. Place one probe of the multimeter on the first terminal (e.g., “Cyl 1”) and the other probe on known good ground, such as the engine block or a metal bracket. Record the resistance reading displayed on the multimeter.

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Step 8: Repeat for Other Terminals

Repeat Step 7 for each remaining secondary terminal on the coil pack. Note down the resistance readings obtained for each cylinder.

Step 9: Compare Resistance Readings

Compare the resistance readings obtained in Step 8 with the manufacturer’s specifications. If any resistance readings significantly deviate from the specified range, it indicates a faulty secondary winding.

Step 10: Inspect for Physical Damage

While testing the coil pack, visually inspect it for any signs of physical damage, such as cracks, burns, or corrosion. If you notice any such damage, it is a strong indication of a faulty coil pack that requires replacement.

Step 11: Reconnect Electrical Connections

Once you have completed the testing and inspection, reconnect all the electrical connections to the coil pack. Ensure the connections are secure and properly seated. Now, you know how to test ford coil pack with multimeter.

Signs of a Faulty Ford Coil Pack

The ignition coil pack is crucial in operating a Ford vehicle’s ignition system. A faulty coil pack can lead to various performance issues and can negatively impact the overall driving experience.

1. Engine Misfires

One of the most common signs of a faulty coil pack is engine misfires. Misfires occur when the coil pack fails to deliver the necessary voltage to the spark plugs, resulting in incomplete combustion. 

You may experience a noticeable loss of power, rough idling, or a vibrating sensation while driving. Engine misfires can damage the catalytic converter and other components if left unaddressed.

2. Difficulty Starting the Engine

A faulty coil pack can make it difficult to start the engine. When the coil pack is not functioning properly, it may not generate enough voltage to create a spark in the spark plugs, leading to extended cranking or a failure to start altogether. This issue is more likely to occur when the engine is cold or has been sitting for an extended period.

3. Decreased Fuel Efficiency

A faulty coil pack could be blamed if you notice a sudden decrease in fuel efficiency. When the coil pack malfunctions, it may not deliver a strong enough spark to ignite the air-fuel mixture properly.

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As a result, the engine may run rich, consuming more fuel than necessary. Monitoring fuel consumption and addressing significant changes can help identify potential coil pack issues.

4. Illuminated Check Engine Light

A faulty coil pack can trigger the check engine light on your Ford vehicle’s dashboard. The engine control unit (ECU) monitors the performance of the ignition system, including the coil pack. 

If it detects irregularities, such as misfires or voltage inconsistencies, it will illuminate the check engine light to alert you of a potential problem. It is essential to have the vehicle’s diagnostic system scanned to retrieve the specific error codes and identify the cause of the issue.

5. Rough Idle

A faulty coil pack can lead to a rough idle, where the engine may feel unstable or shake more than usual when the vehicle is at a standstill. The inconsistent spark delivery from a faulty coil pack can disrupt the engine’s smooth operation at low speeds.

If you notice a significant change in the idle quality of your Ford vehicle, it is recommended to have the ignition system, including the coil pack, inspected.

6. Engine Stalling

In severe cases, a faulty coil pack can cause the engine to stall while driving. If the coil pack fails completely or intermittently, the engine may lose power abruptly, resulting in stalling.

If you experience engine stalling, it is crucial to have your vehicle inspected and repaired promptly to prevent potential accidents.

7. Increased Emissions

A failing coil pack can negatively affect combustion, leading to increased emissions. Incomplete combustion can result in unburned fuel being expelled through the exhaust system, causing higher levels of pollutants.

If you notice excessive smoke, a strong odor from the exhaust, or fail an emissions test, it is essential to have the ignition system checked, including the coil pack.

FAQs

How many ohms does a coil pack have?

The number of ohms in a coil pack can depend on the specific make and model of the vehicle. However, a typical range for the primary coil resistance is between 0.2–3.0 Ω, while the secondary coil resistance can be between 5–20 kΩ.

What is a 1.2 or 0.8 ohm coil?

A 1.2 or 0.8 ohm coil refers to the resistance value of a specific coil used in vaping devices or electronic cigarettes. These values indicate the coil’s electrical resistance, which affects the amount of power delivered and the resulting vapor production.

Different resistance values provide varying heat and vapor production levels for a customized vaping experience.

What is the resistance of a good coil?

The resistance of a good coil in an automotive ignition system usually falls within a range of 5–20 kΩ. This resistance allows for properly generating a high-voltage spark to ignite the mixture in the engine cylinders.

If the resistance deviates significantly from this range or there are significant differences between terminals, it may indicate a faulty coil requiring replacement.

Conclusion

In conclusion, testing a Ford coil pack with a multimeter is a straightforward process. By following the steps mentioned earlier, such as disconnecting the electrical connector, setting the multimeter to the ohms setting, and measuring the resistance between terminals, you can determine if the coil pack is functioning properly. 

Remember to compare the resistance values with the specified range for a good coil. The coil pack is likely in good condition if the readings are within range. However, if the values are outside the range or significantly different between terminals, it may indicate a faulty coil pack that should be replaced. We hope now you know how to test Ford coil pack with multimeter.