hey guys, been awhile. My truck has been parked since early spring. i tried to fire it up today but the fuel pump isnt working. i had my car boosting it as the battery was dead. im not sure what the pin numbers are on the plug, but there are 5 wires. going from one side to the other, i had 1-2 volts, 9-10 volts, 13 volts, dead, dead. or both ground?

this is with the key on. do these numbers look right? im guessing the pump is just stuck, but i want to rule out lack of power first

thanks

 

I just went through this on my 96 3.9l. The voltage was there, but unless the engine is running, it disappears so quick I thought it wasn't there. I ran a jumper in place of the fuel pump relay to force voltage to the pump. The pump wouldn't do a thing like this, but a test light would light up. On the 96, there are only 4 wires hooked up in the 6 wire connector. Two for the sending unit and two for the pump. IIRC, 1 and 6 are the pump and 3-4 are the sending unit. I also measured resistance across the fuel pump and it was open.

Keith

 

I just finished up rewiring my fuel pump. you should have 12v at the pump when the key is turned to the on position. it will shoot up then drop. once you start cranking it over it will supply 12v to the pump. here is a wiring diagram to help you out.
The PCM grounds voltage to the fuel pump relay, which then kicks over to complete the a141 circuit. a141 runs from the pdc along the driver side fender where it branches off behind the firewall thru c116. it then comes back out of the firewall and connects to the lower wire loom at c207. at c207 it changes to a61. this then runs back along the driver side truck and is mounted to the frame. eventually it gets back to the pump and attaches from there. I have a crude picture for you of the pump:



Now this pump had a walbro module on it. a carter module is different in the shape of the connector. the carter is a more flat connector vs this walbrow that is more square. find the pin that plugs into that point and thats your power pin. Unless it was redone, the wire should be green with a black tracer and is a 16gauge wire.

Good luck, let me know if you need anything else.

 

thanks ill try getting someone to cycle the key and see if i get 12v at another wire.

 

no problem. The other option is like what kturner said and use a jumper wire on the power output of the fuel pump relay. that is what I did to aid on my troubleshooting. The power output would be the pin closest to the top of the PDC, it runs horizontal if you are standing at the driver fender of the truck looking down into the PDC. Jump B+ to that pin and it will power all the way down the line for you to check at the pump connector.