Testing The Ignition System (1998-2003 3.9L Dodge Dakota)

TEST 4: Testing The Ignition Coil For Spark

In this test section, we're gonna' check for spark directly on the ignition coil's tower.

As you can see in the photo, the spark tester is placed on top of the ignition coil's tower. I'm using a small piece of vacuum hose to secure the spark tester to the ignition coil's metal terminal.

If the spark tester sparks, then you can conclude that the ignition coil's high tension wire is bad and needs to be replaced (if it did not spark in TEST 3).

If the spark tester does not spark, then the next step is to make sure that the ignition coil is getting battery power (TEST 5).

These are the test steps:

1. 1

   Disconnect the high tension wire that connects to the ignition coil.

2. 2

   Connect the spark tester to the ignition coil's tower with a small piece of vacuum hose (see photo above).

3. 3

   Ground the spark tester directly on the battery negative (-) terminal with a jump start cable.

4. 4

   Have your helper crank the engine.

5. 5

   The spark tester should spark.

Let's examine your test result:

CASE 1: The spark tester sparked. This is the correct test result.

This test result lets you know that the ignition coil is good. You can also conclude that the ignition coil's high tension wire is bad if you have:

• Confirmed that none of the spark plug wires have spark in TEST 1.
• Confirmed that the ignition coil's high tension wire did not spark in TEST 3.
• Confirmed in this test section that the ignition coil does spark.

CASE 2: The spark tester DID NOT spark. The next test is to make sure that the ignition coil is getting 10 to 12 Volts.

For this test go to: TEST 5: Making Sure The Ignition Coil Is Getting 12 Volts.

TEST 5: Making Sure The Ignition Coil Is Getting 12 Volts

If you've reached this point, your test results have confirmed that:

• None of the spark plug wires are sparking (TEST 1).
• The ignition coil's high tension wire is not sparking (TEST 3).
• The ignition coil is not sparking (TEST 4).

In this test section, we're gonna' make sure that your 3.9L Dodge Dakota's ignition coil is getting 10 to 12 Volts.

The wire that feeds these 10 to 12 Volts is the dark green with orange stripe (DK GRN/ORG) wire of its 2-wire connector. In the photo above, this wire is labeled with the number 2.

We'll do a simple multimeter voltage test on the DK GRN/ORG wire to test for the presence of these 12 Volts.

CAUTION: To check for the presence of 12 Volts you must crank the engine. Be careful and take all necessary safety precautions!

These are the test steps:

1. 1

   Select Volts DC mode on your multimeter.

2. 2

   Disconnect the ignition coil from its electrical connector.

3. 3

   Connect the red multimeter test lead to the DK GRN/ORG wire.

4. 4

   Connect the black lead of the multimeter to the battery (-) negative terminal.

5. 5

   Have your helper crank the engine while you observe the multimeter.

6. 6

   You should see 10 to 12 Volts on the multimeter.

Let's analyze your test result:

CASE 1: 10 to 12 Volts are present in the DK GRN/ORG wire. This is the correct test result and it lets you know that your 3.9L Dodge Dakota's ignition coil is getting power.

Since your Dodge Dakota's ignition coil does not fire spark, the next step is to check that the ignition coil is receiving an activation signal. Go to: TEST 6: Testing The Ignition Coil's Activation Signal.

CASE 2: 10 to 12 Volts ARE NOT present in the DK GRN/ORG wire. Without power the ignition coil will not fire spark.

This lack of spark will be caused by one of the following:

• An open-circuit problem in the DK GRN/ORG wire between the ignition coil's connector and the ASD relay.