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

TEST 4: Testing For Spark At The Ignition Coil Pack (Paired Cylinders)

NOTE: This test section only applies if you have two spark plug wires that connect to paired cylinders (#1 and #4, or #2 and #3) that didn't spark in TEST 1.

What we need to figure out now is whether the no-spark result in TEST 1 is caused by bad spark plug wires or by the ignition coil pack itself.

We'll do this by checking each coil pack tower for spark, one at a time, which will tell us indirectly if the spark plug wires are good or if the coil pack is bad.

These are the test steps:

1. 1

   Remove the spark plug wire that did not spark from the coil pack.

2. 2

   Place the spark tester directly on the coil pack tower for that wire (see the example in the photo above).

3. 3

   Connect the spark tester to the battery negative (-) terminal using a battery jump start cable.

4. 4

   Have your helper crank the engine.
   
   CAUTION: The engine may start, so be careful.

5. 5

   You'll see one of two results: Spark or NO spark.

6. 6

   Remove the spark tester and reconnect the wire to its coil pack tower.

7. 7

   Repeat the same spark test on the other coil pack tower —the one that connects to the second non-sparking wire you identified in TEST 1.

Let's take a look at what your test result means:

CASE 1: You got spark from only one tower. That result is telling you two important things:

• The coil pack itself is shot —because it should be firing both towers in that paired set, not just one.
• The spark plug wire of the tower that did spark is also bad (since this wire didn't spark in TEST 1).

Replace both the coil pack and all four spark plug wires to solve this issue.

CASE 2: You got spark out of both towers. That's exactly what you want to see —it proves the coil pack is alive and well.

We can correctly conclude the the spark plug wires themselves are fried (bad) since they didn't spark back in TEST 1. Replace all four spark plug wires with a new set to solve this problem.

CASE 3: No spark from either tower. This result usually points to one of two things: a bad coil pack, or the coil pack not getting an activation signal for the towers that didn't spark.

If the no-spark pair belongs to cylinders 1 and 4, go to: TEST 6: Checking The Activation Signal For Coil A (Cylinders 1 & 4).

If the no-spark pair belongs to cylinders 2 and 3, head over to: TEST 7: Checking The Activation Signal For Coil B (Cylinders 2 & 3).

TEST 5: Making Sure The Coil Pack Is Getting IGN 12 Volts

In this test, we're going to make sure the coil pack is getting 10 to 12 Volts at female terminal 2 of its 3-wire connector.

The wire that delivers this IGN power to terminal 2 is the dark blue (DK BLU) wire of the connector.

To see if power is being delivered to the coil pack, we'll do a simple multimeter voltage test at terminal 2 with the key in the RUN position (but with the engine off).

NOTE: Be careful when probing the female terminal with your multimeter test lead. If you spread or damage that female terminal, you'll have to replace the connector.

Let's start:

1. 1

   Disconnect the coil pack from its connector.

2. 2

   Turn the key to the RUN position but don't crank the engine.

3. 3

   Put the multimeter in Volts DC mode.

4. 4

   Connect the black multimeter test lead to the battery negative (-) terminal.

5. 5

   Gently probe the front of terminal 2 with the red multimeter test lead.

6. 6

   You should see 10-12 Volts on your multimeter.

Let's find out what your test result means:

CASE 1: 10 to 12 Volts are present at terminal 2. Perfect —that's exactly what you want to see, and it proves the coil pack is getting the 12V IGN feed it needs to function.

With IGN power confirmed at terminal 2, we now need to check that the fuel injection computer is actually triggering (activating) both coils inside the pack (coil A and coil B). Head over to: TEST 8: Checking Coil A And B Activation Signals.

CASE 2: 10 to 12 Volts ARE NOT present at terminal 2. Check your connections and run the test again just to be sure.

If you still don't see IGN power at terminal 2, then the coil pack itself isn't the reason your Escort or Tracer won't start. Without that 12-Volt feed from the DK BLU wire, the coil pack simply won't fire spark.

The next step is to troubleshoot why that IGN power feed is missing. Once you restore those 12 Volts to the circuit, the ignition coil pack will function again.

TEST 6: Checking The Activation Signal For Coil A (Cylinders 1 & 4)

Up to this point, you've confirmed the following:

• In TEST 1, the spark plug wires for cylinders 1 and 4 aren't sparking.
• In TEST 4, the coil pack towers for those same spark plug wires didn't spark.

So the next step is making sure coil A —the half of the pack that produces spark for cylinders 1 and 4— is actually receiving an activation signal.

On the 1991-1995 Escort or Tracer, this activation signal comes from the ignition control module (ICM). On the 1996 vehicles, this one comes directly from the fuel injection (FI) computer.

That coil A activation signal is delivered by the dark green with yellow stripe (DK GRN/YEL) wire at terminal 1 of the 3-wire coil pack connector.

We can easily check for the presence of that signal (at terminal 1) with a 12-Volt test light.

NOTE: Use a regular 12-Volt test light with an incandescent bulb to check for the coil's activation signal. If you don't have one, this is the one I recommend —you can buy it here: Lisle 28400 Heavy Duty 12 Volt Test Light (Amazon affiliate link).

Alright, let's start:

1. 1

   Disconnect the coil pack's 3-wire connector.

2. 2

   Clip the alligator lead of your 12V test light to the battery negative (-) post.

3. 3

   Probe female terminal 1 of the coil pack connector with the tip of the test light.
   
   Confirm that terminal 1 actually connects to the DK GRN/YEL 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. 4

   Have your helper crank the engine.

5. 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.

Let's find out what your test result means:

CASE 1: The 12V test light flashed ON and OFF the whole time the engine was cranking. That tells you the FI computer is sending the ignition coil A activation signal to the coil pack.

If you've already checked the following, the ignition coil pack is bad and needs to be replaced:

• No spark from the spark plug wires on cylinders 1 and 4 (TEST 1).
• No spark from the coil towers for cylinders 1 and 4 (TEST 3).
• The ignition coil A activation signal is present at terminal 1 when cranking the engine (this step).

When it comes time to replace it, 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 A isn't getting its activation signal from the FI computer.

Most of the time, this missing signal comes down 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).