Fuel Pump Amperage Draw Test (2004-2010 4.6L, 5.4L V8 Ford F150, F250, And F350)

  • By: Abraham Torres-Arredondo
  • Created: 04 August 2025
  • Updated: 04 August 2025
  • Articl Id: 1551
Fuel Pump Amperage Draw Test (2004, 2005, 2006, 2007, 2008, 2009, 2010 4.6L, 5.4L V8 Ford F150, F250, And F350)

In this tutorial, I'm gonna show you how to figure out the fuel pump's current draw by checking its internal resistance on your 2004–2010 Ford F-150, F-250, or F-350 pickup (with the 4.6L or 5.4L V8 and an FPDM).

Now, why should you care about the fuel pump's amperage draw? Because if it's pulling too much current —even though the pump still runs— it can (and usually does) burn out the Fuel Pump Driver Module (FPDM).

This simple resistance check can save you a lot of headaches. It'll help you spot a failing pump (one that's working too hard) before it damages the FPDM —or deep-frys the brand-new one you just put in.

Contents of this tutorial:

APPLIES TO: This tutorial applies to the following vehicles:

  • 4.6L V8 Ford F150: 2004, 2005, 2006, 2007, 2008.
  • 5.4L V8 Ford F150: 2004, 2005, 2006, 2007, 2008.
  • 5.4L V8 Ford F250: 2005, 2006, 2007, 2008, 2009, 2010.
  • 5.4L V8 Ford F350: 2005, 2006, 2007, 2008, 2009, 2010.

MORE FUEL PUMP DIAGNOSTIC RESOURCES: You can find fuel pump circuit wiring diagrams, related fuel pump tests, and the inertia switch tests in this section:

Why Check Fuel Pump Amperage Draw?

One thing you don't hear much about when it comes to Ford's returnless fuel system —with the fuel pump driver module (FPDM)— is just how sensitive these systems are to a worn out fuel pump with high current draw.

This applies to any setup that controls the Ground side of any motor (be it a fuel pump or a radiator fan motor) with pulse-width modulation (PWM).

And when I say sensitive, I mean it. If the fuel pump starts pulling more amps than it should, the FPDM is gonna get cooked and the engine is not gonna start due to a lack of fuel.

This sucks because the pump might still be running and building pressure just fine —but if it's drawing too much current, it's basically a time bomb for the FPDM. That module might already be damaged, or it's about to take its turn on the chopping block.

To break this down a bit, all electric motors naturally draw current (Amps) while they run:

  • A healthy, brand-new fuel pump draws just enough to get the job done.
  • Over time, the internals wear down —the brushes, bearings, and bushings— which means more friction, and more current needed to keep spinning.
  • Eventually, the pump gives out completely. But sometimes, it keeps running —while pulling way more amperage than it should.
  • In a traditional setup, that'd blow the fuse and nothing else is damaged electronically.
  • But with a PWM-controlled system like on these F-Series pickups, there's no fuse guarding the circuit in the usual way. So if the pump starts over-drawing current, the FPDM's components overheat and burn out.
    • This, right here, is hands-down the biggest flaw in this design.

I've seen it more than a few times —someone bypasses the FPDM to see if the pump still runs. It does. The engine fires up. So the module gets blamed and swapped out.

But the problem wasn't the module. The pump was pulling too many amps. And that brand-new FPDM? Toast —usually within 24 to 48 hours. This is more common than you think.

That's why it's so important to test the pump's internal resistance —and the good news is, you can do this easily with a multimeter. From there, a quick Ohm's Law calculation will tell you how much current the pump is drawing.

If that number hits 15 Amps or more, you've found your problem —and dodged a pricey do-over on another FPDM.

Checking The Fuel Pump's Internal Resistance

Checking The Fuel Pump's Internal Resistance. Fuel Pump Amperage Draw Test (2004, 2005, 2006, 2007, 2008, 2009, 2010 4.6L, 5.4L V8 Ford F150, F250, And F350)

Alright, let's dive in and get this test done:

  1. Unplug the fuel pump driver module (FPDM) from its 6-wire harness connector.
  2. Turn your multimeter to the Ohms setting.
  3. Take the red meter lead and touch it to female terminal 4 on the connector.
    • Terminal 4 is the wire that feeds battery power (+) to the fuel pump.
  4. Now take the black meter lead and connect it to female terminal 2 on the same connector.
    • Terminal 2 is the Ground wire for the pump (–).
  5. Take note of the resistance reading shown on your multimeter.
  6. Now it's time to do a little Ohm's Law math to figure out the fuel pump's current draw:
    • Just divide 12.5 by the resistance value you measured. That gives you the amperage.
    • For example, if you measured 0.4 Ohms, your math would be: 12.5 ÷ 0.4 = 31.25 Amps. That means the pump is pulling 31.25 Amps.
  7. The key number to remember: The pump's calculated draw should be under 15 Amps. If it's above that, the pump's working too hard and you're looking at an FPDM killer.

More Fuel Pump Troubleshooting Help

FUEL PUMP PRESSURE TESTS:

FUEL PUMP INERTIA SWITCH TESTS:

FUEL PUMP DRIVER MODULE (FPDM) TESTS:

FUEL PUMP CIRCUIT WIRING DIAGRAMS:

F150:

F250 And F350:

More 4.6L, 5.4L V8 Ford F150, F250, And F350 Diagnostic Tutorials

You can find a complete list of diagnostic tutorials and wiring diagrams for the 4.6L/5.4L V8 F-Series pickups in this index:

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

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