Hello, ford ranger 2008 2.5tdci ecu not responding. I`ve replaced ecu kit, but problem is still the same. all fuses and relays ok. can`t find wiring diagram of ecu. I would check power on ecu plug.

Did you check the fuse circuit for voltage, use a testlite or something.
I posted part of headlamp wiring. You understand your dimmer switch is involved in the circuits.

OK YOU HAVE REPLACED RELAYS AND FUSES ARE GOOD.DOES THIS TRUCK HAVE A TRAILER WIRING HARNESS ADDED TO IT? HAVE YOU CHECKED/REPLACED THE MULTI-FUNCTION SWITCH?

the power wire to your relay or pump is very weak or grounding take a reading with an ohm meter continuity one lead from fuse other on ground

Hello,

In your power distribution box in your engine compartment (Ford recommends

disconnecting your battery before servicing fuses / relays in PD BOX )

fuse # 9 - 20 amp mini-fuse for fuel pump relay and RAP module

relay # 5 - is the fuel pump relay in your PD BOX

also , the fuel pump inertia (shut off) switch is in the right front passengers

footwell by the right front kick panel.

Thanks..

Hi, if the car runs with the jumper wire, maybe the wire from the ECU is bad. The pump is powered by the 30 amp fuse #1 in the box under the hood. The relay coil is powered by the EEC power relay, and receives it's ground connection from the ECU. If fuse 1 is good, odds are the relay is not getting the ground signal. You can verify this by connecting a test light to the positive battery terminal and probing the relay socket. The pump terminal will dimly light the test light, and when the key is on the ground signal from the ECU should make the light bright. If you don't get this light, either the ECU is not turning the pump on, or the wire from the ECU is bad. Going back to my first question--does the car run with the jumper? If yes, I would guess the wire is bad. If no, I would say there is a reason the ECU is not trying to turn on the pump--like maybe a security system or safety interlock. An easy way to force the relay to come on is to cut the tan/light green wire from the ECU and ground the side that goes to the relay. The pump will run when the key is on, but the ECU will noit be able to shut it off. Please let me know if you have questions.

relays or fuses for relays

If you are looking for a method of preventing the vehicle from being stolen, a better approach is to cut off the ignition supply to the engine management unit or ECU.. Use a circuit diagram of the ECU wiring to determine the ignition feed or feeds and then use a relay to interrupt those feeds. You can switch the relay using a hidden switch or through a vehicle alarm or anti theft device. Disconnecting the starter can be defeated under the hood by shorting the starter solenoid but cutting the power to the ECU cannot easily be bypassed. One word of warning though, DO NOT cut any wires unless you are 100% certain that the wires you are cutting are the correct ones because you can cause the ECU to set fault codes in its memory which can seriously affect the driveability of the vehicle. If you have any doubts, consult a qualified person..

you might have blowed blulbs check that also there might be what is called a fuse link in the wiring

Look under the hood.
There is a large relay which should have some info about lights on it.
I had this exact problem with my dodge ram

I have wiring diagram. Respond with your email address or fax number and I will sent it to you.