No Power to Fuel Pump??

[Wes17]

Hey guys I'm new to the site but really need some advice!
i just bought my 98 ranger a couple weeks ago and i pulled it into my garage to swap out a radio in it (probably unrelated) but when i went to crank it back up it wouldn't start. turns over fine but wont start.
I've replaced the fuel pump relay, fuse pump relay fuse, and also the fuel pump itself and it still wont start. I'm not getting any power to the fuel pump for some reason. The only other thing i can thing of is maybe the PCM isn't commanding power to the relay. Do you guys have any other suggestions before i try and replace the PCM?? thanks in advance! and help is appreciated!

 

[Mikel89us]

There should be an impact switch somewhere that cuts power, its possible it got jarred or unplugged while you were working on it. Its worth a look. I can't tell you where it is though, my truck is a little older.

 

[Wes17]

yeah the inertia switch was the first thing i checked, just forgot to mention it in the first post. thanks for the reply though!

 

[Mikel89us]

No problem, check the connectors everywhere from the tank to the front.

 

[vstar650ca]

yeah the inertia switch was the first thing i checked, just forgot to mention it in the first post. thanks for the reply though!

Unplug your inertia switch and run a wire between the electrical connectors to be sure the switch is not the problem,don,t go by the red button.Good luck

 

[Kenneth S]

unplug your inertia switch and run a wire between the electrical connectors to be sure the switch is not the problem,don,t go by the red button.good luck

x2 ^^^^^

 

[RonD]

The PCM only provides 2 seconds of fuel pump power when key is first turned on.

Any other time there will be no power to the fuel pump, until engine has started, then PCM provides power to fuel pump based on RPM, speed and load, so on and off power.


You could try jumping 12volts to inertia switch, key off, listen for pump to come on, if it does then pump and wire from there is OK.
Then pull out Fuel Pump relay, key off, there will be 4 contacts, with key off only 1 will have 12volts, the power from fuel pump fuse, jumper the 12v from fuel pump fuse to inertia switch wire.
If you can hear the pump come on then inertia switch and wire to relay is OK.

With FP relay still out, turn on key, another FP relay contact should now have 12volts, that's the relay power, it comes from the EEC(PCM) relay located next to the FP relay.
The one remaining contact is the ground control from the PCM.
If you don't have the second 12v contact then check EEC relay.

The PCM grounds FP relay to turn it on.
Put 12v test light or volt meter on these two contacts, place it so you can see light or meter from cab, turn key off and on, you should get light or 12v for 2 seconds each time key is turned on.
If you don't then go to PCM and check it's connections, you can find the Pin assignments for your year on line.
Test FP relay ground by grounding that pin connector with key on and listen for fuel pump.