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Printed Schematics, location drawings, and connector pin outs, from service manual, related to Fuel Pump system. Studying to determine how to empty the remaining quarter tank of 2 yr old fuel, by running pump and pump the fuel out of the car, into a gas can.

Haynes manual suggests the PCM provides ground to Fuel Pump Relay in fuse box beside battery to run the pump.
Says: PCM runs pump, when PCM sees electrical pulses from the Cam Synch. ie. when the engine is running / turning.
Will try that.

But study of schematics also shows a Fuel Pump / System Module near the back of the car, through which power and ground are provided to the fuel pump, and also with control signals / wires going back to the PCM.

Also shown is an Inertial Shut off switch with manual Reset button. ( shuts off fuel pump if it senses a collision / impact ).

Looking also for convenient spot / or Connector, if necessary, near the pump, to hot wire power to the pump directly.
Looking under car, I have found a connector on the front right corner of the tank, accessible underneath, and looks like the wires are the correct colours, per the schematics, to disconnect, gain access, and hot wire / provide power directly to run the pump.

A hose in the engine bay, from the fuel supply, fuel rail connection, would go then, to a gas can. Run pump remotely. Empty tank. ... In theory .

Investigating.
So on a 2000, the PCM talks to the fuel pump driver module (behind the trunk liner on the passenger side, north of the inertia switch). PCM sends the requested duty cycle to the module. Module interprets this, and switches on the grounding side of the circuit using PWM to provide the necessary current to the pump to meet the requested duty cycle. Power is always supplied through the intertia switch from the fuel pump relay when the key is switched to run. Black with pink stripe is your power input on the module, and black is the switched ground that provides current to the pump. There's also a return wire, where the pump sends another signal back to the PCM to confirm that it's doing what it was asked to. Cam synchronizer only has to do with injector pulse timing, not so much fuel pressure output.

IMO simplest way to run the pump at full speed to drain old fuel, is to disconnect the input line at the fuel filter, aim it into your bucket, and then just unplug the connector to the module and use a jumper wire from the power wire to the ground wire (black with pink stripe to black). Will need the key on to do this of course. You'll probably get a B1233 for loss of communication with the FPDM, but it's easily cleared.

I'm glad you figured out you had a grounding issue though, the PCM ground wire in particular gets pretty nasty over time. I measured mine and saw 200mv of voltage drop, so I'll be doing the same as you did to rule out future issues.
 

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Discussion Starter · #22 ·
Empty Old Fuel out of Gas Tank. (Here is how I did it)

2000 Ford Taurus SE

Most connectors, wires, modules near the back of the car, related to the fuel pump, are under seats or behind panels or in the trunk - and a little difficult to get to. Require removal of panels etc.

So looking under the car, ahead of the right rear wheel, (passenger side) I saw a connector clipped with two plastic pins, up at the Right Front corner of the Gas tank.

I cleaned up the wires to see the colours, and colours looked correct, according to what info I had from the schematics I printed from the service manual.

It's tight up there, but I just popped the two plastic studs and that let me pull the connector down a little.

Still too tight, not enough length to disconnect the connector there and pull it down to work / gain access at the connector pins.

So I just left the connector connected, and pulled back the outer black plastic sheath to expose some more wire length before the connector, where I could work on it.

I took two steel straight pins from the sewing kit, and pushed them through the center of the two wires I needed to gain access to.

Then connected two test leads with small alligator clips to the straight pins, to gain an electrical connection.

Insulated over the Power straight pin and alligator clip with a piece of plastic bag, to ensure it does not short out under there, while I work on it / connect power to it later.

The schematics for the car fuel system: 303-14-00-010, Electronic Engine Controls, Gasoline Engines
( for the 2000 Ford Taurus ), told me that the following wire colours were the correct ones:

1. Pump power ( +12 V DC ) : White with Red Tracer

2. Pump Ground : ( Negative, -ve, Ground ) Black with Pink Tracer

So I connect my 12V DC battery charger to the correct leads on the outside and hear the pump run.

Great.

(the car had to be jacked up a bit, at that rear corner, & Safety stand put there, of course, to have enough room to get under there and work on it. )

The Fuel Supply to the fuel rail in the engine compartment was disconnected, plastic flange with two 7mm hex bolt heads, the blue o-ring removed and a 5/16 clear plastic hose plugged in, down to a 20 litre gas can on the floor nearby.

clear hose so I can see the fuel run, or stop running when empty.

Hook up the power, and watch the fuel empty, 20 litres approx in 15 minutes.

Tank empty.

this method separates the power from the fuel by a safe distance, so you don't light yourself up / start a fire.

The electricity is near the back wheel. the fuel comes out near the front of the car.

then when done, put in 20 litres fresh good fuel, ran it a bit more to prime through the fuel line.

then primed through the fuel rail via the schrader valve too.

fresh fuel up to the fuel rail, for then next starting attempt.

no guarantees, careful what you do. have a fire extinguisher handy. be careful.
 

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Yeah, sorry about that, I gave you the wrong colors for the needed items, lol. My memory isn't the best sometimes, but at least you're smart enough to get the diagrams and not trust morons on the internet :) Glad you got it done though, jumping it at the fuel tank connector works great as well since you're already under there to drain the fuel.

But I have to ask, did the car work and run correctly now?
 
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