Wiring Diet

[icoulabeenav8]

I am replacing the Corvette tanks with aluminum tanks. That means the fuel tank harness which is connected to the connector beneath the UHFB can be disposed of right? I am connecting directly from the float sensor in the new tank to the gauge so my thought is that the harness can go... unless the PCM still requires some sort of connection to be happy?

[VRaptor SpeedWorks, LLC]

You could still wire according to the manual and just use the wires in the donor fuel harness to connect to your new sender......or run new wires. Either way will work. No, the ECU does not need to see the fuel level sender, but it does need to control the fuel pump....and all of that wiring already exists in the donor harness, so it seems to me that it would be easier to just use the donor harness if you already have it there.

[beeman]

I'm guessing he's running an external fuel pump?

[icoulabeenav8]

My donor harness looked like it had been to the moon and back. One wire plus grounds seems like the easiest way to go. Isn't the gray wire at location A12, connector C3 beneath the UHFB the fuel pump wire activated by the relay inside the UHFB? I may have misremembered its location because I am away from my Corvette manual.

I will be running the FiTech retrofit drop in pump with a Holley Hydramat pickup which serves as a prefilter also. The Fitech is 3 1/4" in diameter and will just reach down to the full depth of the tank (15"). It fits on the ledge on the back of the aluminum tank perfectly. SO, it solves several problems: No external pump and additional hoses - one hose direct to the filter plus a return hose and one wire besides ground, no EFI reservoir needed because of the Hydramat. Much valuable real estate saved. Much work avoided. Probably cheaper than an external setup also.

https://fitechefi.com/wp-content/uploads/2020/09/50015-Instructions.pdf

https://www.holley.com/products/fuel_systems/hydramat/

[VRaptor SpeedWorks, LLC]

It's been probably decade since I wired up a GTM with the donor UHFB....so not sure on the pin # for the fuel pump.....but yes, it should be a gray wire if memory serves. So, yes, your plan should work just fine to simplify things.