JD X485 fuel pump not running

[Zebrafive]

03:45 am here so Good Morning.

That K12 relay is controlled by the 560-Red wire. Where does that come from?? You can measure the voltage on that wire also.

K12 is the EFI Power Module Relay, as the name implies it powers the EFI module. 560 red wires comes from the Ignition Interlock Module, fuse F5. Which is powered by the Ignition switch when the key is in RUN.

 

[Zebrafive]

Thought I ran out of fuel, but added fuel and then could not hear the fuel pump run when the ignition key turned to on.

Service tech manual pages give schematics of electrical and test points to check. Indication there is a fusible link (F6) and fuse (F7) in the wire (221 red) to the pump.. cannot find where fuse (F7) is located.

Heard the fuel pump kick on when starting the x485 upon leaving the shed.

May have to remove the fender deck and check if voltage going to the fuel pump.. if so, then will plan to replace the pump.

Just had a thought tho, that if the fuel gauge sensor works, then that indicates there is power to the fuel pump..

Attached files show the schematic with the fusible link and fuse feeding the 221 red wire. The next file shows this 221 red wire going to the EFI Module Power Relay and the Fuel Pump Relay, then on to the 651 pink/blk wire at the Fuel Sensor and Fuel pump. The Sensor gauge shows the added fuel so assume there is power at that fuel tank location.

Any additional thoughts much appreciated.

The red 221 wire at K12 relay is always "hot", unless F6 fusible link or F7 fuse is "open" See if you have voltage at red wire 221. If so, F6 & F7 are OK, if not F6 and or F7 are "open" Or you have a broken wire.

 

[beenthere]

Thanks for the tip.
If I put 12v on the fuel pump pnk/blk wire at the fuel pump connector, then I should hear the pump run? It does not. Gets 12v for 2-3 sec when ignition key turned to on, but no response from the pump. Leads me to think the pump needs replacing.
Still possible for another part to be failing?

edit: To add to that, get 10-11 volts at this wire when cranking on the engine.

 

[Spanner]

Ok, the point about diagnostics is to check everything first before splurging to replace parts unnecessarily. AS we read so often on this forum people replace starter motors and batteries and alternators before checking their connections and then find a poor Earth/Ground etc.
So checking relays etc is 'free' first before buying a pump or module etc.

Having said that, This X485 EFI is a model we don't get imported here so I'm not familiar with it. Working off the snippets from your Wiring schematic we are progressing it seems.

The "Power for 2 seconds" implies either a relay is 'dropping-out' or a digital component (Module?) is failing.

So carry-on checking the power circuit and the remaining 2 relays needed if you can.

You have the benefit of the schematics in your possession which is good.

Edit: When applying 12v to the FP at the connector on fuel tank ensure you also apply an independent Ground/Earth from the Black wire back to the battery. This eliminates any issues with "Ground" in the loom or chassis.

 

[Zebrafive]

Thanks for the tip.
If I put 12v on the fuel pump pnk/blk wire at the fuel pump connector, then I should hear the pump run? It does not. Gets 12v for 2-3 sec when ignition key turned to on, but no response from the pump. Leads me to think the pump needs replacing.
Still possible for another part to be failing?

edit: To add to that, get 10-11 volts at this wire when cranking on the engine.

Have you checked for voltage on BOTH sides of the black connector (pink/black wire) if not, bad connection.

 

[beenthere]

Yes Z
Just double checked and get 12v when key turned on, and 11v continuous when key turned to start and engine cranking.
Thanks for the pointer.

Not finding any other fails when checking earth ground or the other relays.
Appreciate your thoughts and suggestions. The hunt continues.

 

[Zebrafive]

In your last picture, it looks like the bottom black wire with the female spade connector is the ground wire. I would check it, maybe make up jumper wire (female spade connector, fork or ring connector for battery) and run from battery negative to the male spade connector on the pump.
If that does not work, time to pull the pump and see if any broken wires.

 

[beenthere]

Thanks Z
Tried that, and same results.. have no pump action.. 12v on the VOM and ground jumper wire. Would assume now pump for sure.. tks

 

[Spanner]

That's what i was saying in #24.
Power the pump and earth it without disassembly. The fewer times you loosen/tighten the screws in the plastic tank (Brass thread inserts in plastic) the better imo.
Edit: That seems definitive. I'd be interested in the state of the filter 'sock' when you get it out pls.

 

[beenthere]

Will take some pics upon removal.. and I wondered about what the bolt screwed into.. maybe I'll get three brass inserts to put in when the 8 bolt fuel pump comes.. Hopefully tomorrow.

Appreciate the feedback and assistance.