TEST 2: Testing The Ignition Coil's High Tension Wire For Spark
In this test, we're gonna' test the ignition coil's high tension wire for spark with a spark tester.
The photo above shows exactly how to connect your spark tester to the ignition coil's high tension wire.
If the spark tester sparks and you got a no-spark test result from all four spark plug wires (in TEST 1) then you can conclude that the four spark plug wires and the distributor rotor are defective and need to be replaced.
If the spark tester does not spark then your next test is to test for spark directly on the ignition coil's tower (TEST 3).
These are the test steps:
- 1
Disconnect the high tension wire that connects to the middle tower of the distributor cap.
NOTE: This is the high tension wire that connects the ignition coil to the distributor cap. - 2
Connect the HEI spark tester directly on the high tension wire's metal terminal (see photo above).
NOTE: The other end of the high tension wire must remain connected to the ignition coil. - 3
Ground the spark tester, using a battery jump start cable, to the battery negative (-) post.
- 4
Have your helper crank the engine.
- 5
The spark tester should spark as the engine cranks.
Let's take a look at what your test results mean:
CASE 1: The ignition coil's high tension wire sparked. This is the correct and expected test result and tells you that your 2.5L Dodge Dakota's ignition coil and its high tension wire are not defective.
You can conclude that the four spark plug wires and distributor rotor need to be replaced if you have:
- Confirmed that the four spark plug wires did not spark in TEST 1.
- Confirmed that the ignition coil's high tension wire does spark (TEST 2).
CASE 2: The ignition coil's high tension wire DID NOT spark. The next step is to test for spark directly on the ignition coil's tower. For this test, go to: TEST 3: Testing For Spark Directly On The Ignition Coil Tower.
TEST 3: Testing For Spark Directly On The Ignition Coil Tower
We're gonna' remove the high tension wire that's connected to the ignition coil and place the spark tester directly in the ignition coil's tower (just as it's shown in the photo above).
The correct and expected test result is for the spark tester to spark as the engine is cranked.
If the spark tester sparks and the ignition coil's high tension wire did not spark in TEST 2 then you can conclude that the ignition coil's high tension wire is bad.
If the spark tester does not spark then the next step is to check that the ignition coil is getting 10 to 12 Volts DC (in TEST 4).
These are the test steps:
- 1
Disconnect the high tension wire that connects to the ignition coil.
- 2
Place the HEI spark tester directly on the ignition coil's tower (see the photo above).
- 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 hold the spark tester in place in the ignition coil's tower.
- 5
The spark tester should spark as the engine turns if the ignition coil is functioning.
Let's examine what your test result means:
CASE 1: The ignition coil sparked. This is the correct and expected test result and tells you that your 2.5L Dodge Dakota's ignition coil is not defective.
You can conclude that the ignition coil's high tension wire is bad if you have:
- Confirmed that the four spark plug wires did not spark in TEST 1.
- Confirmed that the high tension wire did not spark in TEST 2.
- Confirmed that the ignition coil does spark (TEST 3).
CASE 2: The ignition coil did not spark. Without spark the engine will not start in your 2.5L Dodge Dakota.
The next step is to make sure the ignition coil is getting 10 to 12 Volts DC. For this test, go to: TEST 4: Making Sure The Ignition Coil Is Getting Power.
