i have a 04 with the intank lift pump.. i got the bed off and lift pump out.. wondering how to test the electrical connection well i know how to test it... its 4 pins.. what i need to know is what each pin should be at i only get 12v out of 1 pin.. and nothing from the others... just making sure im getting proper voltage before i toss in a new lift pump

 

If you do replace it, I would recommend a draw straw kit and a frame mounted lift pump. Remember two of those wires are for the fuel gauge. I'll see if I can find a diagram. You would need to leave the old pump in the tank for the fuel gauge part of it. Remember too that the pump getting voltage and running freely isn't a sign that it's working. You really need a pressure gauge on it to know for sure.

 

On the pump, with the catch side of the connector facing up, 1 is on the left and 4 on the right.

1-Ground
2-Sensor ground
3-Fuel level Sensor signal
4- Fuel pump relay output

So I would say test for voltage between 1 and 4, the outside pins.

 

voltage only to the senser the pump itself no power... i ran a hot wire to the pump pin truck starts and run... pump is fine... troubleshooting the lack of power... fuel pump relay ???

 

so i guess the new issue is why isnt the plug getting the voltage ? and ideas on where to look i keep reading there isnt a relay for the fuel pump... information is very limited it would seem

 

The pump should run for about 20-30 seconds or so when the key is bumped. After that it shuts off, so obviously the power would shut off. I take it the truck isn't running? I don't know what kind of tester you have, but my volt meter has a setting to hold the reading at the max voltage. So I could connect the meter, press the max hold button, then hop in the cab and bump the key, let it do it's thing, then hop out and see what voltage was stored. If yours wont do this, maybe see if you can get a helper to bump the key while you watch or make a 12 volt test lamp you can see form the cab.

 

On an 04 truck, that in-tank pump would have been added after the truck was built, and when the original engine-mounted pump failed. There will be a relay for this pump, probably hanging off the firewall by a tie strap, and the wiring will be an obvious add-on under the hood, and not part of the truck's engine harness. Follow the wiring, it will plug into the factory lift pump wiring close to the fuel filter. There should also be an inline fuse with this wiring, probably attached to the battery terminal or PDC. The add-on wiring will then run down the firewall along the driver side frame rail, where it will tap into the factory harness's bulkhead connector that runs rearward to the tank. Check it all out; your problem will be there somewhere.

 

i have the bed off and i have long cords on my volt meter lol i can sit in the truck with the Probes on it.. it gets no power when your first turn it on. or at all.. the only way the truck will run at all is if i run a hot jumper to the pump..

 

correct it has the after market in tank set up... ill check all out that you suggested... and bad side effects if i wind up running a new hot to the pump? of course off the fuse panel for the key on .... besides the fact that it wont just turn off at that point

 

If it had the retrofit pump installed then the power wire is connected to a fuse pigtail left side battery. Check the fues first on that wire. Could also be a bad relay should be mounted to fire wall on left side just follow the wire you'll find it.

 

left being driver side ?

 

correct on drivers side positive terminal should be a black wire that goes to a relay fuse is in that wire

 

my hero i owe you a beer!!! **** lil Fuse was Toast!!!!! starts right up!!!! thanks brother!

 

didnt the 4.5 get the in tank pump?

 

correct the 4.5 did.. but my 04 has a MFG date on the motor of 03 so it had to be retro fitted