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Old 03-12-2016
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Join Date: Mar 2016
Location: atlanta, ga
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Icon5 Fuel pump wont turn on

Can the ignition not turn the fuel pump on? I was told this. My 88 ranger was fine all week then when I went to crank it Thursday night the fuel pump wouldnt turn on. I put on a new fuel pump, new fuel pump relay, no corrosion wires, theres no fire going to the fuel pump.
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Old 03-13-2016
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There is a fuse or fusible link that powers the fuel pump motor, 30amp
The Fuel pump relay closes to send that 30amp power to the fuel pump.

The computer controls the Fuel pump relay.
When you turn on the key the EEC Relay closes(click), this sends power to the EEC(computer), fuel injectors, Spark system, and fuel pump RELAY(not fuel pump).
When computer gets power it will GROUND the fuel pump relay for 2 seconds, but only for 2 second, it is a safety feature.
Then computer waits for engine RPMs to be above 400, it will Ground fuel pump relay then and leave it Grounded(ON) until key is off or RPMs drop below 400.

I would test if Fuel Pump relay is working first.
Go here: Ford Ranger - Testing EEC-IV Equipped Engines

Look at second drawing down, that is the OBD connector, found in engine compartment.
Usually drivers side near firewall, but can be passenger side or even below battery, it is part of wiring harness, just hangs there.

In the drawing you see the Fuel Pump slot labelled.
That slot is connected to the Computer's Ground wire for the Fuel Pump RELAY.
So if key is on, and you GROUND that slot with a jumper wire you should hear Fuel pump relay "click" closed, and fuel pump should start.
If you hear the "click" but no fuel pump sound then it could be a blown fuse/fusible link.

If you don't hear a click then EEC relay could be the problem, turn key on and off a few times listen for the EEC relay click, EEC relay has brown base, fuel pump relay a green base.
There is also a 30amp fuse for EEC Relay.

If fuel pump relay is "clicking" closed then next stop will be inside the cab, passenger footwell.
There is an Inertia switch just at or above carpet line in passenger footwell, can also be in the kick panel.
It is small, maybe 2x2 inches and has a button on the top.
The inertia switch will cut fuel pump power in an accident, sudden stop, roll over, button is to reset it temporarily, once it "trips" one time it needs to be replaced or it will "trip" again on a slight bump or if you slam the door, lol, reset button is just for temporary use.
Get volt meter, or test light, with key on and jumper wire grounded to fuel pump relay is closed, test for voltage on BOTH sides of the inertia switch, if only one side has power then replace inertia switch.
If both sides have power then replace fuel pump or get to wiring under the truck to check voltage there.

1988 can have TWO fuel pumps, one in the tank and a high pressure pump in the frame rail under drivers seat for fuel injection use.
Ford added a factor splice near this added high pressure pump in the frame rail, this splice can fail so neither pump gets power.
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