fuel pump not turning on???

[MUDDING B-3000]

ok so im coming down to the last little bit of tinkering to finsh my trail truck an you kno when you turn the key over to ON an hear the pump primer well my truck doesnt do that so i got the multi meter out an tested the voltage at the 4 terminals on the connector at the pump an the black was ground, purple/black only had .14 V an that wire runs to the fuel inertia switch, 4.59 V to the yellow an white wire ( i think), an nothing to the last wire? so would there be a cut in those wires somewhere to not allow full voltage to them? the batter is fully charged. an the pump works i tested it with a 12v source an it turned on when i touch the terminal that the black an purple/black wire go to?

an one more question, with my 92 ranger xt cab 4x4 4L i had a bunch of wires cut under the seat an didnt kno what they were for so i check out the exact same truck at the wreckers an those wires run to like a theft device hidden behind the driver side re jumper seat, with this not in my truck would it cause my truck not to turn over cuz im having wiring problems with the truck not turning over like its a faulty clutch interlock switch but i jumped that out an it still wont turn over?
i can get it to turn over when i jump the started relay out but the ignition key wont turn the truck over.

 

[Viva*the*Ranger]

Have you took your VM to your relay to see if it's doing it's job? And I could be wrong, but I doubt those cut wires have anything to do with your problem here. How and when did this issue start? Did you buy it like that?

 

[Psychopete]

Your pump is only going to run for 1-2 seconds 2 times each. This is hard to catch on a DMM (maybe even with an analog). I believe there is a way to jumper the fuel pump circuit constantly at the diagnostic connector, or use a solid 12v source if you're careful to figure out where the circuit is broken. Also doesn't hurt to have a vehicle specific wiring diagram to aid in diagnosis.

Pete

 

[MUDDING B-3000]

well when i bought the truck it had no motor tranny engine harness, was just a body frame an a skyjacker6" lift an 4.56 gears in the diffs an a bunch of cut wires. i was goin to swap everything over to my mazda but decide to keep this an make it a trail truck. so i bought a engine tranny tcase an engine harness from an exact truck, but boat load of wires are just cut everywhere so it trying to figure out where they go an if any of them are important or not. but i am almost done the truck but it wont turn over or the starter wont click or anything, so thought that theft device would cause it to not work, one thing that makes me think yes is that the wire with the push on connector that goes to the top poll on the starter relay goes to the connector that is cut in my truck but it should run to that theft thingy. like the other trucks

 

[sryan]

I had the same problem with my fuel pump not kicking in and found the ground wire from the computer that connects to the negative terminal of the battery broke free................Just a thought

 

[Psychopete]

top poll on the starter relay

Is it by chance a R/LB wire? Where exactly are the wires cut, in the interior under the dash or under the truck by the transmission?

Pete

 

[MUDDING B-3000]

^^ ya its the red/ltb but i checked for continuity to find the other end of the wire an its a red/white wire an it goes into a connector right under the cigarette ash tray on the firewall inside the truck. but theres no wire coming out of the connector?

 

[Psychopete]

^^ ya its the red/ltb but i checked for continuity to find the other end of the wire an its a red/white wire an it goes into a connector right under the cigarette ash tray on the firewall inside the truck. but theres no wire coming out of the connector?

I would really recommend trying to get a hold of a vehicle specific diagram, library might have on or Helm Inc. sells them. On both my '88 A4LD and '90 AOD, most of the NSS circuit is R/LB, but the other side of the switch was white/pink. The white/pink spliced back into a red/light blue wire within the mainharness - which came back to the dash plugs at the drivers firewall in a different plug to finally go to the starter solenoid. Wiring colors could be different (actually looking at a generic diagram incidates this is probably true) and circuit could be slightly different, not well verse with the wiring for that engine or year.

Pete

 

[MUDDING B-3000]

like i have one of those haynes manuals but it doesnt help any with the wiring or i just cant figure it out lol. an you were saying that the fuel pump only runs for a second an not always when the truck is on?

 

[Ranger-92XLT]

Don't know if this applies to your situation, but my Ranger had a similar problem when I first got it (no fuel pump ignition). Tried a lot of things, but it turned out it was the inertia switch (it's a "switch" that gets tripped if you should get into an accident; the jolt of the hit flips the switch and kills your fuel pump electrical supply in order to prevent fuel fires). It turned out that someone had given me quite a bump in a parking lot (I'm guessing) and that flipped my switch. On my '92, the switch is simply a red reset button on the passenger side interior underneath the carpeting.
Hope this helps!!

 

[MUDDING B-3000]

^^^ thats wat i was thinking an i checked the volts to the pump with that on an off an i only get .14 V when its off like alowing fuel to the motor an 0V when its triped. i even tried jumping it out an that still didnt work.

 

[AllanD]

Do the wires under your drivers seat come through a gromet in the floor?

If so those wires and the black plastic control unit with the LED on it have NOTHING to do with an antitheft system on a Gen2 Ranger.... thats the controller unit and wiring for the electronic shift transfer case.

AD

 

[MUDDING B-3000]

well i do have a electric shift t case an need the wiring so that black thing is for the t case? but the red/ white wire that i was talking about goes to that black box to? or could it have something to do with the push button to switch from 2-4 wd? type thing?

 

[Psychopete]

Hayes manuals suck for wiring - I couldn't tell you unless I had the vehicle specific diagrams in front of me. Library would probably have something, or get one from Helm Inc. There a lot of things that need to happen for the fuel pump to come on. The computer controls the fuel pump, this is only why it primes temporarily when the key is first put to 'run'. I would first start with getting the safety circuit working first (signal to the starter solenoid) and verifying if the computer is getting power or not.

Pete

 

[MUDDING B-3000]

ok thanks alot for the help. is there an easy way to check if the computer is getting power?

lol im good at mechanical crap but when it comes to electrical wiring im a retard, an i really appreciate the help.