TEST 2: Testing For Spark Directly On The Ignition Coil Tower
Now that you have checked and confirmed that there's no spark coming out of the ignition coil's high tension wire, the next step is to check for spark directly on the ignition coil tower.
If the ignition coil sparks (at this point), then we can conclude that the high tension wire is bad.
Yes, the ignition coil's high tension wire can stop transmitting spark and make you believe the ignition coil is bad.
If the ignition coil does not spark, then the next step is to make sure that the ignition coil is getting power.
These are the test steps:
- 1
Disconnect the high tension wire that connects to the ignition coil's tower.
NOTE: This is the high tension wire that connects the ignition coil to the distributor cap. - 2
Place the HEI spark tester directly on the ignition coil tower.
- 3
Ground the spark tester, using a battery jump start cable, to the battery negative (-) post.
- 4
Have your helper crank the engine as you secure the spark tester on top of the ignition coil tower with the battery jump start cable.
- 5
The spark tester should spark as the engine turns if the ignition coil is functioning.
Let's take a look at what your spark tester test results mean:
CASE 1: The ignition coil sparked away. This is the correct and expected test result and tells you that your Nissan D21's ignition coil is not defective.
If the ignition coil's high tension wire did not spark in TEST 1, then you can correctly conclude it's defective and behind your Nissan D21's 'no-spark no-start' problem. Replace the ignition coil's high tension wire.
CASE 2: The ignition coil did not spark away. The next step is to make sure the ignition coil is getting power. For this test, go to: TEST 3: Making Sure The Ignition Coil Is Getting Power.
TEST 3: Making Sure The Ignition Coil Is Getting Power
So far, your tests have confirmed that:
- All four spark plug wires are not sparking.
- The ignition coil's high tension wire is not sparking (TEST 1).
- The ignition coil's tower is not sparking (TEST 2).
In this test section, we're gonna' make sure that your Nissan D21's ignition coil is getting battery power.
The wire that feeds power to the ignition coil is the black with white stripe (BLK/WHT) wire of the ignition coil's electrical connector.
NOTE: You can find a 1992-1994 2.4L Nissan D21 ignition system wiring diagram here: 1992-1994 2.4L Nissan D21 Pickup Ignition System Wiring Diagram.
Let's get started:
- 1
Disconnect the 2-wire ignition coil connector.
- 2
Connect the red multimeter test lead to the BLK/WHT wire of the ignition coil connector.
NOTE: Don't probe the front of the connector, or you'll damage the female terminal. Use a back probe or a wire piercing probe to check for battery power. - 3
Connect the black multimeter test lead to the battery negative (-) post.
- 4
Have your helper turn the key to the ON position.
- 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 the power transistor (ignition control module) is sending the ignition control signal to the ignition coil. For this step, go to: TEST 4: Making Sure The Power Transistor Is Activating The Ignition Coil.
CASE 2: The ignition coil IS NOT getting battery power. This tells you that the ignition coil is not working due to a lack of battery power.
Your next step is to find out why this battery power is missing and restore it. Once battery power is restored, the ignition coil should function again. The following wiring diagram should help you: 1992-1994 2.4L Nissan D21 Pickup Ignition System Wiring Diagram.