OK guy i drove the truck yesterday ran fine today it will not start. everything works but the fuel pump not kicking on..
any ideas i tried the fuel safety switch, the relay, the fuses nothing helped the fuel pump works if u hot wire it.

 

They you need to ring out the wiring to the pump. If the pump is good.

Check the connector under the drivers seat -- if you have one. It really helps us troubleshoot if you would at least give the year of your Ranger -- we're not psychic, lol.

Anyway, there's a bulkhead connector under the drivers seat that you can drop from underneath the truck. All the wiring to the back runs through it. It's not an uncommon problem for this to go. Unhook your battery when you do it, then clean up any corroded pins and hit them with WD40 to boot. If you pack them full of dielectric grease, Noalox, or other corrosion prevention compound for electric circuits, it may help keep you from further trouble if that's the problem.

It would be nice to confirm that the fuel pump relay goes on or not.

However, the relay is controlled by the PCM (if you have one -- again what year?...) and if the signal doesn't get to the relay, the thing won't run.

Welcome to the board though -- nightmare of a Ranger or not!

 

sorry its a 99 3.0 flex fuel... the relay does not click on.. and the anit theft light goes
crazy..the relay is getting power from the fuse.but after that nothing.

 

Wow. Okay that's a problem. Sounds like you have a wiring problem or a bad relay. The anti-theft light might be an indicator. You could be missing a ground somewhere, or it's corroded. Where's the fuel relay, in the battery junction box? I'm on the laptop and don't have the 99 CD manual with me. You might want to check the grounds around that area. Floating grounds can lead to cross feed between circuits and perhaps that anti-theft light is a clue. Check the wiring from the cutoff switch carefully also. Wish I could remember how that's wired. I'll look tomorrow when I get on the other computer if you haven't found it by then.

 

i looked at everything.. i checked all the grounds.. i changed the relay to one i know was good. heres the wiring diagram

 

its looking like the pcm to me...

 

Good deal! (on posting the diagram that is...not on you thinking it's the PCM...)

How about the PCM power relay (upper left of diagram)? If it does not switch on, the fuel relay gets no power.

When someone turns the key on, one of the fuel relay coil pins should go hot. If not, then you're not getting power to the relay coil.

If the relay coil pin goes hot, but the relay doesn't activate, then the problem is in the PCM or wiring to it.

 

i looked at the pcm relay it seemed fine.im gonna try my friends pcm tomorrow i think that will be my best bet.. do ya think? if that dont work i'll look more into wiring...

 

If the PCM relay comes on AND you verify the power to the fuel relay coil, cool. Is that what you mean when you say it "seemed fine"? Because a bad set of contacts on that could drive your PCM a bit nuts with undervoltage on the line, and cause the problem you're having with the theft light, as well as the fuel pump problem.

But yes, another PCM might help, as long as it's really plug compatible. Don't want to risk hurting a good one, lol.

 

hes got the same year ,make and model..

 

That should work. I'm running a 3.0 here also (not that that helps you, lol...)

 

still seems funny to me that it worked one day and the next it dont

 

Does it still turn over? I had an exploder once that the PATS system failed on and the light went crazy, no start, no fuel pump. Just another opinion though.

 

yes it turns over..
heres another one to add..
the pcm relay clicks when it gets installed with the key on. i know the relay is good b/c it from my bag setup.but the red wire coming from it still has no power. i I'm correct thinking the red wire coming from the pcm relay should have power?

 

You should check fuse 19(top left of the diagram) for power with the ignition on, check both sides of the fuse for power, then go to your power distribution box, pull the pcm relay out, check to see if you have power on the tan/blk wire(you may have to take the PDB apart to access this wire). if you have power on the fuse and the tan/blk, check the ground on the relay slot. If all shows correct, check your yellow wire and the 30A pcm fuse for power. I have seen a fuse cause resistance and not "blow", it can cause enough resistance to affect the operation of the PCM. Make sure you have 12v on this wire at the relay slot. If you do, jump the yellow wire slot to the red wire slot using a 30A fuse in some way, shape, or form. If you hear the pump kick on, pull the fuse out, get a brand new relay, and go on your merry way. if not, check back in...

 

thanks man that was it.. the fuse look good changed it and worked... some one should save this ....

 

Thats where experience comes in handy my friend.

 

very true... thanks again..

 

No problem!

 

Ha ha! That's why I told you to VERIFY that there was power to the fuel pump relay coil. It comes from the red wire.

I erroneously assumed you'd already checked the fuses. That's job one in troubleshooting this stuff, especially when you have a diagram that TELLS you what fuses are involved.

Good Nick on having him check that. I assume too much about a peoples troubleshooting techniques sometimes.

 

i checked all the fuses.. but i never seen one do that before

 

They don't do that all so often -- but it's fooled many people before (including me, lol) so don't feel bad.

But when the power isn't there also -- that's when Sherlock Holmes dictum comes into play: "...when you have eliminated the impossible, whatever remains, however unlikely, must be the truth."