I have a 99 ford ranger xlt 4x4 model....heres my problem the fuel pump fuse in the power distrubution box blows everytime i try and start the truck...i tryed reseting the inertia switch didnt work i then unplugged the inertia switch and tryed to start the truck didnt blow the fuse with the switch unplugged,someone told me if i did this then the wiring from the switch to the relay and up front was good and the wiring from the switch to the fuel pump was suspected bad...i have checked the wires at the fuel pump and they appear good, could use a little help though as far as testing the wires...also could a bad fuel pump maybe be causing this?or a bad inertia switch? is there a second fuel pump on this truck? Does anyone have any info on a wiring diagram for this truck?...any help with this would be greatful..I was considering running new wires from the fuel pump with an inline fuse just to get by for now...? any help would be greatful

 

The pk/bk wire is a straight run to the pump from the inertia switch. You should be able to check the wire for a short to ground with the pump still connected by using a meter.

 

Thanks ken00.....do you or anyone have any information on a wiring diagram for my model truck? Also could my fuel pump just be going out or could a dirty fuel filter or bad inertia switch be causing this?

 

You can look up the wiring diagram in a haynes or other ranger book.
Dave

 

Here's how I might approach it.

Leaving the inertia switch open (off), turn the ignition key to the "on" position and watch for battery voltage at the DG/Y wire leading into the inertia switch. Since the FP circuit will only energize for 1 or 2 seconds when you turn the ignition on (just to prime the fuel system), you may have to turn it on and off every 5 or so seconds to get an honest check of whether there is corresponding battery voltage. If you are getting B+ at the DG/Y wire when you turn the ignition on, then your FP circuit is good from the distribution box up to the inertia switch.

Next you want to turn off the ignition, jumper the inertia switch (don't just plug it back in, use a jumper wire), and then turn the ignition switch to the "on" positon and see what happens. If the fuse blows, then you know the second part of the FP circuit, starting from the intertia switch back to the fuel pump, has fault somewhere. If the fuse doesn't blow, then with the inertia switch still jumpered, try starting the truck. If the fuse still doesn't blow, then you know it's a bad inertia switch.

As Ken said, the PB/BK wire at the inertia switch is where this second part of the FP circuit begins, and it runs straight back to the pump itself.

 

i have a question...does anyone know what color the two wires for the fuel pump are at the tank? i believe there is 8 or so wires conneceted at the tank, some for the tank level, and the other wires iam not really sure what they are....

 

PK/BK = Fuel Pump Power

BK = Ground

BK/OG = Dedicated Ground

YE/WH - Fuel Guage to Fuel Guage Sender Ground

BN/WH = Power to Engine Sensors

RD/PK = Sensor Signal Return

GY/RD = Fuel Tank Pressure Tranducer to PCM

 

ok thanks...also would it hurt any to bypass all that and just run a new set of wires for the fuel pump only, just for a temp. solution?

 

Do you mean use a seperate bypass wire from the underhood relay directly to the fuel pump? If you are proposing that, why not try it out first with a long jumper wire? Run the jumper wire from where the DG/Y wire comes off the relay directly back to where the PK/BK goes.

The only wires you care about with regard to the pump itself are the power (PK/BK) wire and the ground wire (BK). No need to rewire the whole harness connector.

 

ok..thanks i will try doing that..also what is the dg/y wire

 

DG/Y is the wire between the relay and the cut-off switch.

 

cut off switch? are u refering to the inertia switch?

 

yes I am, same thing

 

ok, i think i may have got the short taken care of but i created a new problem i replaced the fuel filter and now it leaks is there an o-ring or something that i may be missing....how can i stop this leak...it appears to be coming from the line from the fuel pump to the filter and it has some tabs in the line to keep it on the fuel filter kinda screwy design i think