Anyone have HOW TO return fuel wiring
- Thread starter r103
- Start date
What system are you running? I'm pretty sure lethal has the wiring instructions on their site for their systems.
I believe you use the "on" wire from the FPDM to trigger two 30A relays one for each pump.. the feed to the relays comes from a 10 gauge power wire from the battery.. I will be doing this shortly.. so I still need to do my research, but from what I can figure its something like stated..
You could do this one of two ways.
Delete the FPDM. Use the DG/YE wire (original power wire for the FPDM) as a trigger for the relays. Advantage: easiest way to wire return pumps. Disadvantage: the pumps will run all the time with the key in the 'on' position even if the engine isn't running.
Retain the FPDM. Use the FPDM's fuel pump wires (BN/PK is positive and RD/BK is negative) to trigger the relay. Advantage: you'll get the fuel pump priming action like stock. Disadvantage: harder to setup. Your tune will need to be setup to run 100% duty cycle at all times when the engine is running to make sure the relay stays energized.
Delete the FPDM. Use the DG/YE wire (original power wire for the FPDM) as a trigger for the relays. Advantage: easiest way to wire return pumps. Disadvantage: the pumps will run all the time with the key in the 'on' position even if the engine isn't running.
Retain the FPDM. Use the FPDM's fuel pump wires (BN/PK is positive and RD/BK is negative) to trigger the relay. Advantage: you'll get the fuel pump priming action like stock. Disadvantage: harder to setup. Your tune will need to be setup to run 100% duty cycle at all times when the engine is running to make sure the relay stays energized.
I have mine wired to the FPDM... Heres my diagram..
theres a thread on wiring it with the fpdm triggering the pumps, they also added a switch so you could turn the key and run the pumps full time to help you set base pressure and other trouble shooting. I plan to set mine up that way
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