TEST 2: Making Sure The Ignition Coil Is Getting 12 Volts
In this section, we're gonna make sure the ignition coil that didn't spark in TEST 1 is actually getting 10 to 12 Volts DC.
You've probably noticed by now that all ignition coils come with a 2-wire connector. Out of the two wires on each of these connectors, one is always a red with light green stripe (RED/LT GRN) wire.
This RED/LT GRN wire is the one that feeds 10 to 12 Volts DC to the ignition coil. It usually connects to the terminal I've labeled with the number 2 in the illustration of the ignition coil pigtail connector above.
NOTE: There's a good chance your multimeter's test lead tip won't be able to probe the metal terminal inside the connector because the terminal's slot is very small. If the test lead tip can't safely probe the terminal, use an adapter on the test lead. Otherwise, you could damage the terminal or the connector, and you'll need to replace the connector.
These are the test steps:
- 1
Disconnect the ignition coil that did not spark from its 2-wire connector.
- 2
Place your multimeter in Volts DC mode.
- 3
Connect the black multimeter test lead to the battery negative (-) terminal.
- 4
Gently probe the female terminal of the connector that connects to the wire labeled with the number 2 (see photo above) with the red multimeter test lead.
- 5
Have your helper turn the key to the ON position.
- 6
You should see 10-12 Volts on your multimeter.
Let's take a look at what your test results mean:
CASE 1: The multimeter registered 10-12 Volts (or the test light lit up). This test result tells you that the power circuit is OK and is delivering voltage.
The next step is to test the Switching signal circuit, go to: TEST 3: Checking The Ignition Coil's Activation Signal.
CASE 2: The multimeter DID NOT register 10-12 Volts (or the test light DID NOT light up). This test result confirms that the power circuit has a problem.
This result eliminates the COP ignition coil as the source of the misfire condition. The power circuit is shared by all of the COP ignition coils.
TEST 3: Checking The Ignition Coil's Activation Signal
For our last ignition coil test, we're gonna make sure the ignition coil that didn't spark in TEST 1 is receiving an activation signal.
To check for the presence of the ignition coil's activation signal (while we crank the engine), we'll use a 12 Volt test light.
NOTE: There's a good chance your 12V test light probe's tip won't be able to probe the metal terminal inside the connector because the terminal's slot is very small. If the test lead tip can't safely probe the terminal, use an adapter. Otherwise, you could damage the terminal or the connector, and you'll need to replace the connector.
Let's get started:
- 1
Disconnect the ignition coil from its connector.
- 2
Connect the crocodile clip of the 12V test light to the battery positive (+) terminal.
- 3
Gently probe the terminal of the connector labeled with the number 1.
- 4
Have your helper crank up the engine as you observe the 12V test light.
- 5
The 12V test light should flash ON and OFF the whole time the engine is cranking and running.
Let's take a look at what your test results mean:
CASE 1: The test light flashed ON and OFF. This test result confirms that the ignition coil's activation signal is present.
This result also indicates that the Coil-On-Plug ignition coil on your Ford E-Series van is bad and needs to be replaced if you have:
- Confirmed that the ignition coil is not sparking (TEST 1).
- Confirmed that the ignition coil is getting 12 Volts (TEST 2).
- Confirmed that the ignition coil is getting an activation signal (this test section).
CASE 2: The test light DID NOT flash ON and OFF. Re-check all of your connections and repeat the test again.
If still no flashing ON and OFF, then this results eliminates the ignition coil as the source of the no-spark condition/misfire, since without the Switching signal the ignition coil will not work.
There are several possible causes for this that I've seen time and time again with the most common being: An open-circuit problem in the wire that feeds the Switching signal between the fuel injection computer and the COP ignition coil. The second most common: A fried fuel injection computer. Although testing these two conditions are beyond the scope of this article, you have at least eliminated the ignition coil itself as the cause of the problem.
Other Common Causes Of A Misfire
Over the past few years I've noticed a few other things that can cause a misfire code to set that are not caused by the ignition coil itself having gone bad. Some of these have already been covered in the article:
- Broken Fuel Injector Connector: The fuel injector connector's locking tab is broken. This is a very, very common problem with all Ford vehicles. So, if you have a broken fuel injector connector locking tab, you've probably have found the cause of the misfire!
- False Contact Problem: The ignition coil connector's female terminals are not making solid contact with the ignition coil's male spade terminals. This issue, often due to human error, likely stems from inserting objects that are too thick into the connector's female terminals, causing them to permanently open up. As a result, this leads to an intermittent false-contact issue.
- Open-Circuit Problem:An open in the wiring has developed somewhere in the wiring-harness that does not let the Switching signal thru'. This is also normally caused by human error after an engine replacement.
- Coolant/Engine Oil Leak: Anti-freeze or engine oil leaking into the spark plug tube and drowning the spark plug and spark plug boot.
- Carbon Tracks: The spark plug boots spark plugs have developed carbon tracks (see image above). These carbon tracks create a conductive path that diverts electricity (the spark) away from the spark plug tip, causing a cylinder misfire. These carbon are usually the result of engine oil leaking into the spark plug tube.
- Broken Ignition Coil Connector: The ignition coil's connector's locking tab has broken. This locking tab is the one that makes sure the connector does not become unplugged from the ignition coil. This tab usually breaks when the ignition coil is disconnected, either to replace it or the spark plugs.
- Low Compression Problem: The engine may have one or more cylinders with low engine compression. I suggest testing engine compression:
- Bad Or Clogged Fuel Injector: There's a good chance that the cylinder misfire issues is caused by a bad or clogged fuel injector. The following tutorials may be helpful:
More 4.6L, 5.4L V8 Ford E150, E250 And E350 Tutorials
There are quite a few 4.6L and 5.4L Ford E-Series van 'how to' tutorials and wiring diagrams that you can check out here:
F-Series Pickups: You can find all of the available tutorials and wiring diagrams for the 4.6L And 5.4L V8 F-Series pickups in this index:
- 4.6L, 5.4L Ford F150, F250, And F350 Index of Articles (at: easyautodiagnostics.com.com).
Crown Vic And Grand Marquis: You can find all of the available tutorials and wiring diagrams for the 4.6L And 5.4L V8 F-Series pickups in this index:
If this info saved the day, buy me a beer!
