How To Test The Ignition Coil (1988-1990 2.5L SOHC Dodge Dakota)

TEST 4: Making Sure The Ignition Coil Is Getting Power

In this test section, we're gonna' make sure that the ignition coil is getting 10 to 12 Volts DC.

The wire that feeds these 12 Volts to the ignition coil is the grey with black stripe (GRY/BLK) wire labeled with the number 1 in the photo above.

NOTE: Power is only available to the ignition coil when the engine is cranking or running. So to check for these 12 Volts you'll need to crank the engine. Be careful and take all necessary safety precautions.

Let's get started:

1. 1

   Place your multimeter in Volts DC mode.
   
   NOTE: The ignition coil can remain connected to its two electrical connectors.

2. 2

   Connect the red multimeter test lead to the terminal labeled with the number 1 in the photo above.
   
   This terminal connects to the GRY/BLK wire.

3. 3

   Connect the black multimeter test lead to the battery (-) negative post.

4. 4

   Have your helper crank the engine.

5. 5

   Your multimeter should read 10 to 12 Volts DC if the ignition coil is getting battery power.

Let's take a look at what your test results mean:

CASE 1: The ignition coil is getting 10 to 12 Volts DC. This is the correct and expected test result.

The next step is to make sure that your Dodge Dakota's fuel injection computer is activating the ignition coil. For this step, go to: TEST 5: Checking For The Ignition Coil Control Signal.

CASE 2: The ignition coil IS NOT getting 10 to 12 Volts DC. This tells you that the ignition coil is not working due to a lack of battery power.

The most likely cause of this missing voltage is an open-circuit problem in the GRY/BLK wire between the ignition coil and the ASD relay connector.

TEST 5: Checking For The Ignition Coil Control Signal

For our last test we're gonna' see if the fuel injection computer is activating the ignition coil.

The ignition coil gets its activation signal on the black with grey stripe (BLK/GRY) wire labeled with the number 2 in the photo above.

This is a very easy test and it's one we're gonna' do using a 12 Volt automotive test light.

If the 12 Volt test light flashes ON and OFF, then you can conclude that the ignition coil's activation signal is present.

Here are the test steps:

1. 1

   Connect the crocodile clip of the test light to the battery positive (+) terminal.

2. 2

   Touch the terminal labeled with the number 2 with the 12 Volt test light's metal probe.

3. 3

   Have your helper crank the engine.

4. 4

   The 12 Volt test light should flash ON and OFF as the engine cranks.

Let's take a look at what your test results mean:

CASE 1: The 12 Volt test light flashed ON and OFF as the engine cranked. This is the correct and expected test result and confirms that your 2.5L Dodge Dakota's fuel injection computer is activating the ignition coil.

You can now conclude that the ignition coil is defective and needs to be replaced if you have:

• Confirmed a lack of spark at all 4 cylinders.
• Confirmed no spark directly on the ignition coil tower (TEST 3).
• Confirmed the ignition coil is getting power (TEST 4).
• Confirmed the ignition coil is getting an activation signal from the fuel injection computer.

Here's a more detailed explanation: If the ignition coil is getting 10 to 12 Volts (TEST 4) and it's getting an activation signal (TEST 5) then it has to spark. Since your test result confirms that it does not spark (TEST 3), you can conclude that the ignition coil is defective.

CASE 2: The 12 Volt test light DID NOT flash ON and OFF as the engine cranked. This tells you that the fuel injection computer is not sending an ignition coil control signal. Without this activation signal the ignition coil will not spark.

This missing ignition coil control signal is usually due to a defective distributor pick-up coil. Testing the distributor pick-up coil can easily be done with a multimeter. You can find the test here: How To Test The Distributor Pick-Up Coil (1990-1995 2.5L SOHC Dodge Dakota).

More 2.5L Dodge Dakota Tutorials

You can find a complete list of tutorials here: Chrysler 2.5L 4-Cylinder Index Of Articles.

Here's a sample of the tutorials you'll find there:

• Oxygen Sensor Heater Test (1993-1995 2.5L Dodge Dakota).
• How To Test The TPS (1993-1995 2.5L SOHC Dodge Dakota).
• How To Test The MAP Sensor (1994-1995 2.5L SOHC Dodge Dakota).
• How To Test Engine Compression (1993-2002 2.5L Dodge Dakota).