tschellinger2

Hey guys, I am currently trying to do the fuel pump wiring for a foxbody with the in-tank pump. I have a 1991 mustang so the fuel pump relay is located under the driver's side seat. I am using a Speartech wiring harness for the ls1 engine and there is a trigger wire for the pump and a fuel pump relay included in the Speartech harness. How do I wire in the trigger wire? Do i tap it into the wiring by the relay or back at the inertia switch in the trunk? I was told I also need to ground the green wire @ the relay after the trigger wire is wired in. Anyone have any advice or guidance as to the correct way to wire the fuel pump? Any help is greatly appreciated. Very close to having this thing running this weekend.

Thanks,

-Taylor

tschellinger2

Is it possible to just bypass the ford fuel pump relay and inertia switch completely by tying that fuel pump signal wire from the GM ecu to the brown/pink wire coming out of the inertia switch in the trunk? If you see in the wiring diagram attached to this post the brown/pink wire is the +12V wire to trigger the fuel pump.

Project GatTagO

iTrader: (7)

Figure out which wire on the Ford relay is the trigger wire, then replace that wire with the with the wire on your Speartech harness. I wouldn't bypass the inertia switch because it is a nice safety feature to have.

I am in Oshkosh...

Andrew

tschellinger2

Tapping into that brown/pink wire after the inertia switch will work, I tested it out earlier. But yeah I hear ya man, I ended up figuring it out now to work with the ford relay and inertia switch. Thanks though!

91foxbodygt

iTrader: (7)

The dark green/yellow wire on the inertia switch is the input. Cut that wire and splice in the fuel pump wire from the swap harness to it.

Cut the tan/light green wire from the Ford fuel pump relay that's under the driver's seat and ground it.

That's it as far as fuel pump wiring.

cagodinez

Hey guys, can you help me figure out where to tap into for the fuel pump 12v coming from my harness. Im working on a 1995 f150 and the wiring is very similar to a foxbody.

cagodinez

Can I simply cut red wire pin 86 and splice in my 12v fuel pump wire coming from my harness? And cut light brown/orange pin 85 and splice in a ground?

Tanus

I would use the power wire that originally powered the ford pump as your trigger wire. that way you keep the factory inertia switch and the on/off operation will be same as the original ford pump. plus its the simplest to wire. (may have been suggested above, I didn't read previous replies)