So I have recently change my fuel pump on my 92 ranger bc I had no power to the pump, and I still have no power to the pump or the pump reset switch, I have changed the pump relay and still nothing, the pump runs if I use a jumper wire, I’ve been told to check the ignition switch, only problem is idk where that is and if that ain’t the problem what else could it be?

 

Welcome to the forum


Does the CEL(check engine light) come on when you turn on the key?

If so ignition switch is OK(it is under the steering column, just FYI)

The ignition switch turns on the EEC relay, next to the fuel pump(FP) relay, the EEC relay powers up the computer(EEC) and also the fuel pump relay, not the fuel pump, just the FP relay
So if computer starts up, CEL comes on, so if that happens the ignition switch is OK, as far as fuel pump relay is concerned

The computer controls the FP relay by GROUNDING it

On the main wiring harness you will find the OBD1 plug, EEC-IV plug, you need to find that plug

Then look here: https://therangerstation.com/tech_library/OBD_I.shtml

second drawing down is the OBD connector
Fuel Pump slot is labeled
That slot is the GROUND for the FP relay, it is hooked to the computers ground wire for FP relay
Turn on the key
Use a jumper wire in that slot to any Ground, when grounded you should HEAR the FP relay "click" closed(key has to be on)

If not then FP relay has no 12v from EEC relay, bad wire in the relays base maybe?

If FP relay clicks but no power to fuel pump then FP fuse is blown, look in engine fuse box for 20amp FP fuse

If FP relay clicks closed and fuel pump does power up then ground wire on pin 22 of computer is bad, it can't turn on the FP relay

You can leave the Ground jumper in place and drive the vehicle, fuel pump will shut off when key is off


FP relay's base should have one slot with 12volt all the time, thats from the FP fuse
With key on it should now have another 12volt slot, thats from the EEC relay

Just a heads up, the computer only Grounds the FP relay for 2 SECONDS when key is turned on, but it will do that EVERY TIME key is turned on
Computer will only Ground the FP relay full time once engine RPMs are above 400, engine started
This is a safety feature in case of an accident, if a fuel line should break, you do not want an electric fuel pump to feed a possible fire, so if a fuel line breaks engine will most likely stall, and when RPMs drop below 400 computer unGrounds the FP Relay