TEST 2: Testing The Ignition Coil's High Tension Wire For Spark
If you got a no-spark test result from all four spark plug wires, then the next step is to test the ignition coil's high tension wire for spark.
If the ignition coil's high tension wire sparks, then you can conclude that the reason that none of the 4 spark plug wires sparked in TEST 1 is due to a bad distributor cap and rotor (with the emphasis on a bad distributor rotor).
If the ignition coil's high tension wire is not sparking, then the next step is to check for spark directly on the ignition coil's tower (in TEST 3).
These are the test steps:
- 1
Disconnect the high tension wire that connects to the center of the distributor cap.
NOTE: The other end of the high tension wire must remain connected to the ignition coil. - 2
Connect the spark tester to the ignition coil high tension wire (as shown in the photo above).
NOTE: You'll connect the spark tester to the end of the wire that connects to the center tower of the distributor cap. The other end of the wire remains connected to the ignition coil. - 3
Ground the spark tester to the battery negative (-) terminal with a battery jump start cable.
- 4
Have your helper crank the engine as you hold the spark tester.
- 5
The spark tester should spark.
Let's analyze your test results:
CASE 1: The spark tester sparked. This is the correct test result.
You can correctly conclude that the distributor cap and rotor are bad (and need to be replaced) only if you have:
- Confirmed that none of the spark plug wires sparked in TEST 1.
- Confirmed that the ignition coil's high tension wire does spark (this test section).
Replacing the distributor cap and rotor as a set should solve the no-start problem on your 1993-1994 2.5L Dodge Caravan (Plymouth Voyager).
If the spark plugs and the spark plug wires are as old as the distributor cap, I recommend you replace them too.
CASE 2: The spark tester DID NOT spark. This tells you that the distributor is not getting spark.
Then the next step is to check for spark directly on the ignition coil's tower. For this test go to: TEST 3: Testing The Ignition Coil For Spark.
TEST 3: Testing The Ignition Coil For Spark
If you've reached this point, you have:
- Confirmed that none of the spark plug wires are sparking.
- Confirmed that the ignition coil's high tension wire is not sparking.
In this test section we're gonna' place the spark tester directly on the ignition coil tower and check for spark.
You'll need to use a small piece of vacuum hose to connect the spark tester to the metal terminal of the ignition coil's tower.
In the photo above, the orange arrow points to the piece of vacuum hose I'm using to connect the HEI spark tester to the ignition coil tower's metal terminal.
These are the test steps:
- 1
Disconnect the high tension wire that connects to the ignition coil.
- 2
Connect the spark tester to the ignition coil's tower with a small piece of vacuum hose (see photo above).
- 3
Ground the spark tester directly on the battery negative (-) terminal with a jump start cable.
- 4
Have your helper crank the engine.
- 5
The spark tester should spark.
Let's examine your test result:
CASE 1: The spark tester sparked. This is the correct test result and it means that the ignition coil is good.
With this test result 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 are sparking (TEST 1).
- Confirmed that the ignition coil's high tension is not sparking (TEST 2).
- 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 4: Making Sure The Ignition Coil Is Getting 12 Volts.
