TEST 3: Testing For Spark At The Ignition Coil Pack
In this test step, your mission is to test for spark directly on the ignition coil pack towers that feed spark to the two spark plug wires (of paired cylinders) that did not fire off spark in TEST 1.
You'll test one tower first and then test the other. The correct test result is for both towers to spark.
If both towers don't spark, then you can conclude that the ignition coil is defective and needs to be replaced.
Let's get started:
- Remove one of the spark plug wires that did not fire off spark from the ignition coil pack.
- Place the spark tester directly on the ignition coil tower, in place of the spark plug wire you just removed (see photos in the image viewer).
- Ground the spark tester with a battery jump start cable to a good engine Ground point or directly on the battery negative terminal.
- Have your helper crank the engine. The engine may start, so be careful.
- You're gonna' get one of two results: Spark or No Spark.
- Disconnect the HEI spark tester from the ignition coil tower and reconnect its spark plug wire.
- OK, now repeat tests 1 thru' 5 on the other ignition coil tower whose spark plug wire did not fire off spark.
Let's see what your test results mean:
CASE 1: You got spark from only one tower. This result lets you know that the ignition coil is bad. Replace the ignition coil.
CASE 2: You got spark from both towers. This result lets you know that the ignition coil is good and that the spark plug wires are bad. Replace all of the spark plug wires as a set.
CASE 3: You got NO spark from both towers. This usually means tht the Switching signal for those two towers is missing.
The next step is to test for the Switching Signal for that particular ignition coil (within the coil pack) that owns the two towers you just got done testing by choosing one of the following:
- If you got No spark from the towers that feed spark to cylinders 1 and 4 go to TEST 5.
- If you got No spark from the towers that feed spark to cylinders 2 and 5 go to TEST 6.
- If you got No spark from the towers that feed spark to cylinders 3 and 6 go to TEST 7.
TEST 4: Testing The Power (12 Volts) Circuit
In this test section we're gonna' make sure the ignition coil pack is getting power.
You can use a multimeter or a 12 Volt test light to test the Power (12 Volt) circuit of the Chrysler coil pack.
To get an accurate test result, I recommend that you use a multimeter.
Alright, these are the test steps:
- The 4 wires in the ignition coil pack's connector are usually sheathed in black electrical tape that has probably turned plastic hard, remove enough of this electrical tape to expose the three wires for testing.
- Disconnect the ignition coil from its electrical connector.
- Put the multimeter in VOLTS DC mode (don't have a digital multimeter? Need to buy one? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing).
- Probe the circuit labeled with the number 3 (see photo in image viewer) with the red multimeter test lead (using an appropriate tool to pierce the wire).
- With the black multimeter test lead probe the battery negative (-) terminal.
- Have your helper turn the key to the ON position and then crank the engine. Continuous voltage is only provided when the engine is being cranked.
- You should see 10-12 Volts on your multimeter, or if you're using a test light, the test light should light up.
Let's see what your test results mean:
CASE 1: If the multimeter registered 10 to 12 Volts DC, then the next step is verify that the Switching signals are present, go to TEST 5 , then do TEST 6, and then do TEST 7. If the all three Switching signals are not present (after testing them in TEST 5, TEST 6, and TEST 7), the most likely cause will be that there's an open-circuit problem in the engine wiring harness or a bad connector somewhere in the engine harness.
CASE 2: If the multimeter DID NOT register 10 to 12 Volts DC, re-check all of your connections and retest. If still no voltage is present, this result exonerates the coil pack. Repairing the cause of this missing voltage will solve the 'no spark - no start' condition of your Chrysler (or Dodge or Plymouth) mini-van. The most common reasons for no Power are:
- The Crankshaft Position (CKP) sensor is bad If the crank sensor is bad, the PCM will not power up the Auto Shut Down (ASD) Relay, which in turn will not power up the ignition coil pack or any other ignition system or fuel system component. You can find the crank sensor test here: Crank Sensor Test (at troubleshootmyvehicle.com).
- A BAD Auto Shut Down (ASD) Relay.
- A blown fuse.