fuel pump wiring

[Ford Builder]

Am wondering where the fuel pump get its feed from my pumps are not working need wiring diagram.

[MikeFleming]

Fuel pump systems (both single and dual) get their power from the fuel pump relay under the drives seat. That relay gets full-time batt + from a yellow wire that also feeds the EEC (Keep-Alive Memory) and the EEC relay. That yellow wire gets power from the starter solenoid batt + side through a 15A fusable link brown lug to starter solenoid). Other side of the fuse link changes to yellow.

[brsvo]

Search for rothfam.com he has all the turbo ford wiring diagrams. I have them on my computer but can't find the link to his page right now.

[Ford Builder]

Well I got the car fired up with a jumper wire across the relay plug the fuel relay is fine I have lost my ground feed from the EEC I need the wire diagram to trace the ground circuit all the power leading to the relay are fine Mike tells me there is a ground wire follows behind the dash cluster though the dash there is a splice that has two a joining wires that may fail before it goes to the EEC now noticed my clock has quit too could the two problems be together??

[MikeFleming]

... Mike tells me there is a ground wire follows behind the dash cluster though the dash there is a splice that has two a joining wires that may fail before it goes to the EEC now noticed my clock has quit too could the two problems be together?? What Mike said is detailed in his post above. The "crimp" I referred to in our conversation is the power side to the EEC KAM, the EEC relay and the fuel pump relay. Since you can get the engine running by jumpering the FP relay, I'd conclude those crimps are good.

The EEC uses pins 20, 40 & 60 as ground wires. They all crimp to the one ground strap they you see when accessing the EEC - it's slightly forward on the inner kick panel metal. Usually held in by a 7mm green hex head screw. Check that lug to EEC 60-pin connector pins 20, 40. 60.

EEC 60-pin connector pin 22 is the FP ground output from the EEC. Check that wire to see it has conductivity to the appropriate coil wire on the FP relay socket.

If those wires are all good, the fuel pump driver transistor in the EEC is probably defective. Swap in a different EEC and test.

[Ford Builder]

Thanks Mike, I will look into my car more in-depth on the weekend and let you know how things pan out.

[MikeFleming]

Also check that the non-ground (EEC) side of the FP relay coil should get 12V+ when ignition is on. If it doesn't get that, I'd check assorted fuses and maybe replace the ignition switch. Fuses/ign switch would also be common to the radio whereas grounds are not (radio ground to dash to chassis are completely separate from grounds for the EEC).

[Raven855]

Did you check the inertia switch?

[MikeFleming]

Did you check the inertia switch? Good point! That is in-line with the FP relay coil circuit!

[brsvo]

If the inertia switch was tripped then the jumper on the relay wouldn't work would it?

[MikeFleming]

If the inertia switch was tripped then the jumper on the relay wouldn't work would it? The inertia switch interrupts the primary side of the relay coil. The coil that pulls the power contacts together. It does not break the power circuit.

[Under Pressure]

Is the relay coil located in the fuse box area?

[MikeFleming]

Is the relay coil located in the fuse box area? The relay coil is part of the relay. When the FP relay coil is energized, the power circuit (aka relay contacts) is completed and +12VDC power is sent to the fuel pump(s).

The ralay has two sides, aka wires or pins. One gets +C12VDC through the ignition switch in the Run or Crank positions through a fuse. It's a VERY low power requirement so there's probably lots of other things on that same fuse (all fuses and functions are covered in the owners manual).

The second side of the relay coil goes to the EEC which decides when to energize the fuel pump(s). Cranking & engine running are about the only conditions that warrant running the pump(s).

In series with one of the above relay coil wires is the inertia switch (I've forgotten whether it's on the power side or the ground side but it's one of those for sure!). It interrupts the coil wire circuit so the relay does not energize.

Mud a little clearer?

[Under Pressure]

I can see clearly now all the rain has stopped.

[Ford Builder]

Well I finely got to my car today and the first thing I checked on the list was the inerta switch, I pulled the plug from the switch and put a jumper wire across the terminals , turn the key on low and behold the fuel pumps fired, with the fuel pump relay pluged in, in short my inerta switch has crapped out. Am calling the dealer to see what new is worth ? Am glad that that's all it was all along. Thanks for all your in put.

[MikeFleming]

Party On, Wayne!!

[Raven855]

If you need a switch, I have one in a car that is totaled. You are welcome to it....

[Ford Builder]

I passed on a new one for now, I found one at local bone yard , Thanks for the offer Raven. life is good again

[Raven855]

Does that mean you're running?

[Ford Builder]

Sorry, yes she is running fine

[MikeFleming]

Sorry, yes she is running fine Not to worry - We can fix that!!!