How To Test The Distributor Pickup Coil (1989-1991 3.9L V6 Dodge Ram Van)

TEST 2: Making Sure The Distributor Pickup Coil Has 8 Volts

So, TEST 1 showed the pickup coil's not flipping between 5 and 0 Volts. Sometimes that happens because it's not getting power —specifically, 8 Volts DC from the engine computer.

So to make sure, we're gonna check if the orange (ORG) wire is actually feeding 8 Volts DC to the pickup coil.

If power's there, we'll move on and make sure the sensor's also got a solid Ground in TEST 3.

Here's how to check for power:

1. 1

   Unplug the pickup coil from its harness connector.

2. 2

   Connect the black lead from your multimeter to the battery's negative (-) post.

3. 3

   Set your multimeter to DC voltage mode.

4. 4

   Turn the ignition key to ON —but don't start the engine.

5. 5

   Touch the red lead to terminal 1 on the connector (check the connector diagram above to ID it).
   
   Make sure this terminal connects to the ORG wire.
   
   NOTE: You're testing the engine wiring harness connector —this one has the round female terminals.

6. 6

   The reading should land somewhere between 7.5 and 8 Volts DC.

Here's how to read what you got:

CASE 1: You're seeing 7.5 to 8 Volts on the ORG wire. Perfect. That means the computer's sending power like it should.

Next up, you've gotta make sure the black with light blue stripe wire has a solid Ground: TEST 3: Making Sure The Distributor Pickup Coil Has Ground.

CASE 2: You're NOT seeing 7.5 to 8 Volts on that ORG wire. Without that voltage, the coil's dead in the water.

Most of the time, that means there's an open-circuit somewhere between the FI computer and the pickup coil along the ORG wire.

Tracking down that break is outside the scope of this guide, but your next move is to trace the wire and repair the open.

TEST 3: Making Sure The Distributor Pickup Coil Has Ground

Alright, so far, you've run two tests and here's what they've told you:

• TEST 1: The signal voltage isn't flipping between 0 and 5 Volts.
• TEST 2: You've got 7.5 to 8 Volts on the ORG wire.

Now for the final check —we're gonna make sure the pickup coil's getting a solid Ground. The wire that delivers it is the black with light blue stripe (BLK/LT BLU) wire on the pickup coil's connector.

IMPORTANT: The Ground comes from the fuel injection computer. Do not connect the BLK/LT BLU wire straight to 12 Volts —you'll fry the computer. The steps below provide a safe, reliable way to check for Ground using your multimeter.

Here's how to run the test:

1. 1

   Unplug the pickup coil from the harness connector.

2. 2

   Connect your multimeter's red lead to the battery's positive (+) terminal.

3. 3

   Set the multimeter to read DC voltage.

4. 4

   Turn the key to ON —don't start the engine.

5. 5

   Use the black lead to carefully probe terminal 2 on the connector.
   
   Double-check that this terminal connects to the BLK/LT BLU wire.
   
   NOTE: You're testing the engine wiring harness connector —this one has the round female terminals.

6. 6

   Your meter should show between 10 and 12 Volts DC.

Here's what those numbers mean:

CASE 1: You're seeing 10 to 12 Volts. That's exactly what we want —it confirms the pickup coil has a solid Ground.

If all your test results line up like this:

• No switching between 0 and 5 Volts in TEST 1,
• You got 7.5 to 8 Volts on the ORG wire in TEST 2,
• And now you've confirmed Ground on the BLK/LT BLU wire...

...then the pickup coil's fried. It's time to replace it.

CASE 2: Your multimeter shows 0 —no voltage at all. That means there's no Ground, and without it, the pickup coil can't do its job.

Usually, that means the BLK/LT BLU wire is broken somewhere between the pickup coil and the computer.

Finding the exact spot is outside the scope of this guide, but your next move is to trace that Ground wire and fix the open.

More 3.9L V6 Dodge Ram Vans Diagnostic Tutorials

I've written quite a few 'how to' diagnostic tutorials for the V8 Dodge Ram van and you can find them in this index:

• 3.9L V6 Dodge Ram Van Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test The Fuel Pump (1989-1991 3.9L V6 Dodge Ram Van).
• How To Test The MAP Sensor (1989-1990 3.9L V6 Dodge Ram Van).
• Throttle Body Temp Sensor Tests (1989-1991 3.9L V6 Dodge Ram Van).
• How To Test For A Blown Head Gasket (1989-2003 3.9L V6 Dodge Ram Van).