I'm in the process of wiring up my car. Have a full Racetronix fuel system with dual pump hotwire kit installed. Also have a piggyback Current Performance harness. Pump one will be triggered by the Holley green output getting spliced into the Current harness so the factory relay setup will function correctly. In the Racetronix harness, a short way back from the battery connections, there are two fuse holders and two 2-wire terminals. They provide two looped plugs with the harness that make a ground circuit to run both pumps off the factory relay. I am only using one, of course. The question I have is, I know I need to set up a ground side switched trigger in the Term X that will turn on when I hit boost, but I'm unsure how to wire it. The terminal will have two wires coming off it, I just need to know how to wire them to the Term X or my CAN I/O box.

 

 

Yep, I know the programming part. I need the wiring part. I have a two wire terminal, but the output from the Term X is one wire. Where does the other wire go? Is it even needed? I'm not sure, which is why I'm asking.

 

Are you SURE the Racetronix setup uses ground to control it?

All the stuff I have seen from them, all use the factory fuel pump power wire to turn on the hotwire relay, but I have not used one of their dual setups.

I am more than slightly confused.

IF it is ground side switched, it should be wired like this;

(low current/control side)
85-switched 12v source
86-ground switched output from the Holley ECU

(high current side)
30-battery or alternator
87-secondary fuel pump power wire

 

This is how it is done. This is wiring into a Dominator but should be the same regardless. Btw since you run a Holley you didn't really need to buy that huge Racetronix harness. You only really needed the bulkhead connector for the fuel sender

 

For secondary pump activation, unplug one of the two ground control jumpers and wire the PCM to pull either the small red or blue wire to ground.
The primary PCM fuel pump power is used to supply + to both the relay coils via the gray wire. This is normally supplied by the factory fuel pump circuit via the IDPH harness.

 

Thanks all for the replies. Seeing the schematic and the reply from Racetronix helped me figure it out. As for not needing the harness, I wanted the heavier gauge wires to power the pumps, as I've had issues in the past with weak pump performance due to inadequate wiring. It all came in a kit I bought from the WS6Store a couple years ago when they were having a sale, so I was able to get everything at a pretty good price.

 

Unless you intend on controlling the pumps via PWM it is best to use the HD harness.
Depending on the model of pump the draw may be too much for the PCM driver.
The relay and fuse in our harness is more robust and much easier/cheaper to repair/replace than a PCM driver.

 

Yes, it's definitely a better set up, which is why I'm using it. Sorry if my reply inferred I wasn't. I'm using the E-85 compatible Racetronix 340s.

 

I've tried doing this and the second pump does not turn on. The output has been tested and is functioning correctly. Pumps are both wired correctly and both function correctly. @Racetronix , is there something I'm missing here? Does pin 86 on the relay need to receive power from the Holley to work?

*EDIT* So, I believe I have figured out the problem. When doing the output testing, I was only testing the individual output, which was working fine. What I failed to realize is unless the Holley main fuel pump output is ALSO triggered, pin 86 on the Racetronix relay is receiving zero voltage from the factory fuel relay, which means the pump won't turn on. I plan to test this when I get home from work.

 

I'm here to confirm that my idea was correct. I disconnected the ground loop from the main pump so it wouldn't turn on, and using the output function on the Terminator, I triggered the main pump. I left it triggered on, and then triggered the secondary pump. This time, the secondary pump turned on. So everything was hooked up correctly after all.