How to test gm coil pack with multimeter

How to test gm coil pack with multimeter.If you are facing any difficulty performing the multimeter test for the GM coil pack, follow the simple method to get the desired results.

How to test gm coil pack with multimeter

If you want to check whether the coil pack emits the exact voltage when the spark is sent out, try using a multimeter to detect any change.

Don’t get confused!

We have brought all the possible detailed procedures to test the GM coil pack for the perfect results.

Let’s start trying it out!

A multimeter is employed to detect any defect in the coil pack. Perform the test based on the following scenarios in case of any defection.

 The most common signs include

  • A rough idle
  • A louder engine
  • A lack of power
  • A drop in revolution per minute
  • A blinking engine light

Procedure for Testing the GM Coil Pack

All you need is a bag of recommended tools and a multimeter device to check the coil at home.


User manual

The specifications lie in the user manual. The specifications help you interpret the results shown by the multimeter.

 Essential requirements

  • Coil pack
  • Digital Multimeter Device
  • ratchet
  • socket

Testing the Coil’s Voltage

  1. Before testing, locate the spade terminal on the coil.
  2. You will find two of them, small in size from the rest of the pack.
  3. Switch on the multimeter.
  4. Connect the red lead of the multimeter to the right terminal and the black one to the left terminal of the GM coil.
  5. After securing all the connections, observe the value on the device screen.
  6. Note down the voltage value and check for specifications.
  7. The voltage between 11- 12 volts indicates that the coil is efficiently working.

Testing The Coil Pack Resistance

  • Start the test by removing the coil pack from the vehicle.
  • Disconnect the negative battery system.
  • Locate the position of the coil pack through the spark plug wires from the plug itself and again to the coil pack.
  • After locating, disconnect the wires.
  • Mark each wire to keep the order back in the right place.
  • After that, use a socket and ratchet to remove the coil from the engine bay.

Testing the Coil’s Primary Resistance

  1. First, test the primary resistance of the coil pack by a multimeter.
  2. Take the meter and set the value of voltage to 10 ohms.
  3. Connect the multimeter to the coil pack.
  4. One leads to the center prong of the coil and the other to the spark plug terminal.
  5. Make sure that the connections are secured.
  6. Observe the readings on the device screen.
  7. If the multimeter showed a value of more than 2 ohms, the coil pack is faulty.
  8. You have to replace the coil pack for better functionality of your vehicle.
  9. If the value is below 2 ohms, let say 0.9 ohms, the coil pack is functioning well.

Testing the Coil’s Secondary Resistance

  1. Now, test the coil pack for secondary resistance.
  2. This time, Set the ohmmeter to 20,000 ohms.
  3. Connect the leads of the multimeter to each spark plug terminal.
  4. Make sure that the connections are secured.
  5. Observe the readings on the device screen.
  6. If the multimeter showed a value of more than 30,000 ohms, the coil pack is faulty.
  7. If the value is below 6000 ohms, let say 3000 ohms, the coil pack is still non-functional.
  8. The value must lie between 6000-20,000 ohms as per specifications.
  9. In this way, you can test the coil pack and interpret the efficiency.
  10. When you have done the test, reinstall the coil pack into the engine bay.
  11. Secure all the electrical connectors back to their place.
  12. Connect the negative battery cable and then close the hood of the vehicle.


To test a GM coil pack, use multimeter voltage and resistance factors. Different values will interpret the efficiency and defects in the coil pack. In case of a defect, replace it with a new coil pack.

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