Ignition Coil Test -No Spark No Start Tests
(Ford 4.9L, 5.0L, 5.8L)

In this article I’ll show you a very simple, easy and highly accurate way to see if the Ignition Coil on your 4.9L, 5.0L, 5.8L Ford F150 (or E150, Bronco, Crown Victoria, Grand Marquis, etc) is fried and causing your vehicle to NOT START or not the cause of the problem.

The test you’ll be doing is an On Car Test done with the Ignition Coil in action. You won’t need any expensive testing equipment to follow the simple step-by-step testing instructions presented here. You’ll need a Spark Tester, a Multimeter, a 12 Volt Test Light, and a helper (to assist you in cranking the Engine).

If you’re looking for the resistance test of the Primary and Secondary Circuits, this article will not help you (in my opinion, the Primary/Secondary resistance test is a complete waste of time and life that does not work around 99% of the time to diagnose a BAD Ignition Coil).

To help you navigate this article a little easier, here are its contents at a quick glance:

1. Important Suggestions.
2. Symptoms of a BAD Ignition Coil.
3. How Does the Ignition Coil Work?
4. IGNITION COIL TEST 1.
5. IGNITION COIL TEST 2.
6. IGNITION COIL TEST 3.
7. IGNITION COIL TEST 4.
8. Why the HEI Spark Tester
9. Related Test Articles.

Important Suggestions

TIP 1: The Ignition Coil Test, I'm gonna show you here, is done with the Engine cranking and so you've got be careful and stay alert. Take all necessary safety precautions.

TIP 2: You'll need a helper to help you crank the Engine. I suggest that you keep him or her outside the vehicle till you need him (or her) to crank the Engine. Your helper should stay outside the vehicle and away from the Ignition Switch before and after you set up the test.

Symptoms of a BAD Ignition Coil

This may seem like a no brainer because the most obvious symptom of a BAD Ignition Coil is a No Start No Spark Condition, but here are a few other symptoms you'll see along with No Spark:

1. None of the Spark Plugs will fire Spark.
2. The Fuel Pump will still work.
3. The PCM will still activate the Fuel Injectors.

The one thing to remember, if you do find out that the Ignition Coil failed, is that the Engine will be flooded with gasoline and this may require that you remove the gasoline fouled Spark Plugs to dry them out (or your vehicle may still not start).

How Does the Ignition Coil Work?

Although the following explanation is not theory heavy or full of big technical words/terms, it will help you to see how the Ignition Coil works.

Knowing a little practical working theory will answer a lot of questions that the article doesn't answer.

It all starts when you turn the key and start cranking the Engine... and in a nutshell, this is what happens:

1. The Ignition Control Module (ICM) and the Ignition Coil get Power (12 Volts).
   1. Power is supplied to the Ignition Coil thru' the wire labeled with the number 2.
2. The Profile Ignition Pickup (PIP) Sensor, which is the Crank Sensor in Fords, gets power from the ICM and as the engine Cranks it starts to generate a Crank Signal (called the PIP Signal).
3. This PIP Signal is then sent to and received by the Ignition Control Module (ICM).
4. When the ICM gets the PIP Signal, it starts to Switch the Ignition Coil ON and OFF by interrupting the Ignition Coil’s Primary Voltage.
5. Once the Ignition Coil gets this Switching Signal, it starts to Spark away and as you're already aware, this Spark gets delivered to the center of the Distributor Cap by a High Tension Wire.
6. By this time, the Fuel Injection Computer is also injecting Fuel into the Engine, which the Spark will ignite... thus the engine starts!S

In the next page we'll jump right into the first Ignition Coil test...