How To Test The Ignition Coil Pack (1991-1996 1.9L Ford Escort, Mercury Tracer)

By: Abraham Torres-Arredondo
Created: 19 September 2025
Updated: 19 September 2025
Articl Id: 22

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TEST 7: Checking The Activation Signal For Coil B (Cylinders 2 & 3)

Checking The Activation Signal For Coil B (Cylinders 2 & 3). How To Test The Ignition Coil Pack (1991, 1992, 1993, 1994, 1995, 1996 1.9L Ford Escort, Mercury Tracer)

Up to this point, you've confirmed two things:

Spark plug wires for cylinders 2 and 3 didn't spark in TEST 1.
The coil towers for those cylinders also failed to spark in TEST 4.

The next step is to find out if ignition coil B —the one that fires spark for cylinders 2 and 3— is getting an activation signal from the ignition control module (1991-1995) or FI computer (1996).

This coil B activation signal is delivered by the brown with red stripe BRN/RED wire, which connects to female terminal 3 of the coil pack's 3-wire connector.

We're gonna use a 12V test light at female terminal 3 (while cranking the engine) to check for this particular activation signal.

NOTE: Make sure you use a standard 12-Volt test light that has an incandescent bulb. If you don't already have one, here's the one I recommend —you can pick it up here: Lisle 28400 Heavy Duty 12 Volt Test Light (Amazon affiliate link).

Alright, let's get to it:

1
Disconnect the ignition coil pack's 3-wire connector.
2
Clip the alligator lead of your 12V test light to the battery negative (-) post.
3
Probe female terminal 3 of the coil pack connector with the tip of the test light.

Confirm that terminal 3 actually connects to the BRN/RED wire of the connector.

NOTE: Be careful not to damage the female terminal with the probe —if you do, you'll have to replace the connector.
4
Have your helper crank the engine.
5
The 12V test light should flash ON and OFF the whole time the engine cranks.

NOTE: Don't worry about what the test light does before cranking the engine —whether it comes on or not. What matters is that it flashes while the engine is cranking.

OK, let's interpret your test result:

CASE 1: The 12V test light flashed ON and OFF the whole time the engine was cranking. This confirms that ignition coil B is getting its activation signal from the FI computer.

You can conclude the ignition coil pack is fried and needs to be replaced if you have confirmed:

The spark plug wires that connect to cylinders 2 and 3 aren't sparking (TEST 1).
The coil pack towers for cylinders 2 and 3 also aren't sparking (TEST 3).
The coil pack is getting its coil B activation signal (this step).

I want to recommend the following coil packs. They're from brands I've used for years without issues:

Standard Motor Products FD487T Ignition Coil (Amazon affiliate link).
Motorcraft - Coil Asy - Ignition DG530 (Amazon affiliate link).

CASE 2: The 12V test light did NOT flash ON and OFF while the engine was cranking. Recheck your connections and run the test again to be sure.

If you get the same result (no flashing), then ignition coil B isn't getting its activation signal from the FI computer.

This missing coil B signal is generally due to one of the following issues:

A bad ignition control module (1991-1995 Escort or Tracer).
An open in the DK GRN/YEL wire between the coil pack connector and the ICM (1991-1995) or FI computer (1996).
A bad fuel injection computer -rare, but it happens (1996 Escort or Tracer).

TEST 8: Checking Coil A And B Activation Signals

Checking Coil A And B Activation Signals. How To Test The Ignition Coil Pack (1991, 1992, 1993, 1994, 1995, 1996 1.9L Ford Escort, Mercury Tracer)

So far, your coil pack tests have confirmed two things:

All four plug wires have no spark (TEST 1).
The coil pack is getting its IGN power supply (TEST 4).

Now it's time to see if your Ford Escort or Mercury Tracer's coil pack is receiving the coil A and B activation signals it needs to fire spark to all four cylinders. These are the signals we need to confirm:

Ignition coil A activation signal —controls spark for cylinders 1 and 4.
Ignition coil B activation signal —controls spark for cylinders 2 and 3.

On the 1991-1995 1.9L Escort or Tracer, these two signals are provided by the ignition control module (ICM). On the 1996 vehicles, these two signals are supplied directly by the fuel injection (FI) computer.

NOTE: To run this test, you'll need a standard 12-Volt test light with an incandescent bulb. If you don't already have one, this is the one I use and recommend: Lisle 28400 Heavy Duty 12 Volt Test Light (Amazon affiliate link).

These are the test steps:

1
Disconnect the coil pack's 3-wire connector.
2
Clip the alligator lead of your 12V test light to the battery negative (-) post.
3
Test terminal 1 (ignition coil A).

Probe female terminal 1 of the connector with the tip of the test light.

Verify that terminal 1 connects to the DK GRN/YEL wire.

NOTE: Be careful not to damage the female terminal with the probe —if you do, you'll have to replace the connector.
4
Have your helper crank the engine. The test light should flash ON and OFF the whole time the engine cranks.
5
Test terminal 3 (ignition coil B).

Move the probe to female terminal 3 of the connector.

Verify that terminal 3 connects to the BRN/RED wire.
6
Have your helper crank the engine again. The test light should flash ON and OFF the whole time the engine cranks.

Let's find out what your test result means:

CASE 1: The 12V test light flashed ON and OFF at both terminals while cranking the engine. This means both activation signals —coil A and coil B— are definitely present.

You can call the coil pack bad and know its time to replace it only if:

TEST 1 showed none of the spark plug wires were delivering spark.
TEST 4 proved the coil pack is getting its IGN power feed.
This test just confirmed both coil A and coil B are being triggered by the PCM.

For your replacement coil pack, I want to recommend the ones from the following brands. These are known automotive brands I've used for years and won't disappoint:

Standard Motor Products FD487T Ignition Coil (Amazon affiliate link).
Motorcraft - Coil Asy - Ignition DG530 (Amazon affiliate link).

CASE 2: The 12V test light never flashed ON and OFF at both terminals while cranking the engine. That result tells you the coil pack isn't getting either of its activation signals. Without these signals, it's not gonna fire spark to any of the cylinders.

The most likely reason both signals are missing will be one of the following problems:

A bad crankshaft position (CKP) sensor (1991-1996 Escort or Tracer).
A bad ignition control module (1991-1995 Escort or Tracer).

Your next step is to check that the CKP sensor is OK and generating its signal.

Other Things That Can Cause A Misfire

Quite a few things can cause the engine to run rough or set a cylinder misfire. So if you've eliminated the spark plug wires, spark plugs, and the coil pack as the source, then in this section I want to offer you a few more troubleshooting tips to get to the bottom of it.

Spark plugs covered in engine oil —The valve cover will leak engine oil onto the spark plugs and spark plug wires. Over time, the oil cooks and forms carbon tracks on the spark plug's porcelain insulator, and those carbon tracks will eventually cause the spark plug to misfire.

Inspect the inside of the wire boots and the ceramic insulator of each spark plug. If you see carbon tracks (like in the photo above), they can't be cleaned off —you'll need to replace the affected parts. This is a case study on this particular type of problem:
- Carbon Tracks Are A Common Cause Of Ignition Misfires.
Low or uneven engine compression —On high mileage engines, compression issues in one or more cylinders will cause a rough idle or a cylinder misfire.

I've written a tutorial that explains how to do a compression test and, more importantly, how to interpret its results to pinpoint a weak cylinder causing the rough idle or misfire:
- How To Test Engine Compression (1991-1996 1.9L Ford Escort, Mercury Tracer).
Clogged or failed fuel injectors —If one or more cylinders aren't getting enough fuel (or any fuel), they're gonna misfire. You'll need to check if you've got a bad or clogged fuel injector on your hands.