[jrjeb]

the fule pump stoped working so we replaced and it still did not work so we checked the wires and fuses and they turned out ok we tested the fule pump with a battery and it worked so does any know what the problem might be
thanks to anyone who replies

[Kallie49]

Did you meter your wires to make sure you have power at the pump? Checking the pump with a battery is great at least you know it works, now you need to run a meter on the electrical system and make sure all of that is functional. Also check the stuff that may have caused the pump to go bad in the first place....clogged/crimped return line, clogged crimped supply, vent, clogged filter, rule out all of your mechanical issues as well... is there a relay on the system? if so is it any good? (I'm shooting from the hip here I dont know squat about exploders)

[smileys35]

I agree, stick the harness conector by the fuel pump with a light tester first and turn the key on. Your supply wire should come on for a few seconds. I had a similar problem with a nissan truck. All the wires were good, the pump was good. The relay was working but it was getting hot while going down the road and was cutting out, and sometimes would not work after shutting the key off for a few seconds. I found the problem by switching the relay with the one from the a/c relay and the truck drove fine. All the relays are not the same though, beware, best thing is to go to the dealer and get a print out of the numbers on the relays for each system. A new one with the wrong numbers will give you the same problems. I've also seen the main engine relay cause the same problems on some cars, they just get rusted on the inside and start sticking. One more thing, if applicable, pull the fuel pump relay out when the truck acts up and stick all four of the prongs with a light tester with the key on the on positon, before crank, and just one of the wires should have power, if none do, the main engine relay is bad. This is of course assuming that all the wires are good in between. Hope this helps.

[docvette]

Doc here,

Check power to the relay COIL, and in / out of the contacts..Best test is substitution with a known good relay..Be sure you have all your 12 volt signals in to the relay.

Next Check the Roll~over switch (if so equipped) and reset if required.

Finally be sure the tank and pump / float egress door is properly grounded to the frame rail.

Doc

[jimfulco]

Got an owner's manual? If so, look up the location of the fuel-pump cut-off switch, or inertia switch. It's probably somewhere in the back of the truck, under an access panel or behind a section of trim or carpet. It has a white or yellow button on top, and you should push it down. If it goes down and stays, it was tripped, and the pump should now work. The switch trips if you have a wreck so you don't have fuel spraying at 50psi on a vehicle that might be on fire. Sometimes they'll trip on a bump, and sometimes they just do it for no good reason.

[cabowabo]

Originally Posted by jimfulco

Got an owner's manual? If so, look up the location of the fuel-pump cut-off switch, or inertia switch. It's probably somewhere in the back of the truck, under an access panel or behind a section of trim or carpet. It has a white or yellow button on top, and you should push it down. If it goes down and stays, it was tripped, and the pump should now work. The switch trips if you have a wreck so you don't have fuel spraying at 50psi on a vehicle that might be on fire. Sometimes they'll trip on a bump, and sometimes they just do it for no good reason.

and sometimes the tires blow up on there own too (firestone tires) lol
the fuel shut off is in the back on the right side behind the panel where your jack is located it has a red button i think red is for fire

[matt167]

fuel pump relay is bad, happens on rangers/ explorers all the time

[jrjeb]

thanks for the replies it turns out the relay was bad so we replaced it and now it works just fine

[matt167]

Originally Posted by jrjeb

thanks for the replies it turns out the relay was bad so we replaced it and now it works just fine

just as I said it was. glad ya got it fixed. a couple people I know have had no start conditions on earlier Explorers and this fixed it, was even discussed on Two Guys garage at 1 time because it is such a common problem.

[docvette]

Originally Posted by docvette

Doc here,

Check power to the relay COIL, and in / out of the contacts..Best test is substitution with a known good relay..Be sure you have all your 12 volt signals in to the relay.

Next Check the Roll~over switch (if so equipped) and reset if required.

Finally be sure the tank and pump / float egress door is properly grounded to the frame rail.

Doc

Doc here,

Good to hear you got it fixed!

It is usually one of the three listed above..the relay being top suspect, close second the roll~over switch.

Thanks for posting back the fix!

Doc

[sbchevfreak]

I've seen lots of fords come in that have just had a fuel pump done to no avail, and all that was wrong was the inertia switch was tripped. Also, ford trucks have a habbit of melting the relay harness connector, and the wires falling out.