EFI to carb, fuel pump wiring question

Radon · 05-01-2002, 12:32 AM

According to :
http://www.jason.fletcher.net/tech/e...b/efi-carb.htm

In order for the fuel pump to work, I need to make a few changes
to the harness in the engine bay.

"On the Black Harness:

----GROUND #97 (tan/light green - 18ga) to a suitable chassis ground. This creates the ground for the primary side of the fuel pump relay.

---Wire #361 (red 16ga) to #16 (the wire you ran to the ignition turn-on above). This creates the positive voltage supply for the primary side of the fuel pump relay."

This is according to his 1990 Mustang, but doesn't seem to apply to my '87 as I don't have wires in those colors..

Does anyone know the color of the wires I'm looking for?

Thanks.

Jeff Chambers · 05-01-2002, 06:36 AM

Do what I did. Use the factory wires, but instead of running them through the fuel pump relay, wire them directly to the fuse panel. I actually routed mine though a rocker switch and a 30amp relay, but they are still the factory wires. When I switched to carb, I actually pulled all the wiring harnesses from the car and completely ridded them of any circuits that I didn't need. Took about 25lbs of wiring out of the car.

Stang951 · 05-01-2002, 08:03 PM

That is alot of freaking wires. I was thinking of doing the same thing, nut I am in no way sure of what can be ditched and what cant be ditched.

Radon - I tried wiring the pump using different instructions and couldn't get it to work with the factory relay. I am about to rewire and try it this way. The main reason that I wanted to do it this way though was to keep the fuel pump cut-off switch. If you dont care about that you could wire it like Jeff Chambers did.

Radon · 05-02-2002, 02:29 AM

I'm simply looking for the easiest route. I'll probably just figure something out tomorrow, so no biggie.

PKRWUD · 05-02-2002, 06:47 AM

What you need to do is first to ground the wire that was the controlling wire from the ECM. This wire is Tan w/ Lt. Green tracer (T/LG). If you cannot find it in the black harness as described, remove the drivers seat and ground it near the fuel pump relay (cut the wire about 6" from the relay, and attach it to chassis ground so that the (T/LG) wire goes from the relay to ground).

Next, you want to splice the wire that used to supply power to the FP relay (through the inertia switch) when the ignition was turned on. Look for a 16 gauge red wire (R) in the black harness as described. Then find the 16 gauge red wire w/ lt. green tracer (R/LG) in the gray harness, as described. Next, splice the two together with a splice connector. If you can't find a 16 gauge red wire (R) in the black harness, look for an orange wire w/ a black tracer (O/BL) instead.

Does this help? If not, tell me specifically what you can and can not find.

Take care,
-Chris

05-01-2002, 06:36 AM	#2
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Do what I did. Use the factory wires, but instead of running them through the fuel pump relay, wire them directly to the fuse panel. I actually routed mine though a rocker switch and a 30amp relay, but they are still the factory wires. When I switched to carb, I actually pulled all the wiring harnesses from the car and completely ridded them of any circuits that I didn't need. Took about 25lbs of wiring out of the car. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

05-02-2002, 02:29 AM	#4
Radon Registered Member Join Date: Sep 2000 Location: Calgary, Alberta, Canada Posts: 68	I'm simply looking for the easiest route. I'll probably just figure something out tomorrow, so no biggie. __________________ '87 Performance Red Notch Carb'd 306 w/ nitrous

05-02-2002, 06:47 AM	#5
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	What you need to do is first to ground the wire that was the controlling wire from the ECM. This wire is Tan w/ Lt. Green tracer (T/LG). If you cannot find it in the black harness as described, remove the drivers seat and ground it near the fuel pump relay (cut the wire about 6" from the relay, and attach it to chassis ground so that the (T/LG) wire goes from the relay to ground). Next, you want to splice the wire that used to supply power to the FP relay (through the inertia switch) when the ignition was turned on. Look for a 16 gauge red wire (R) in the black harness as described. Then find the 16 gauge red wire w/ lt. green tracer (R/LG) in the gray harness, as described. Next, splice the two together with a splice connector. If you can't find a 16 gauge red wire (R) in the black harness, look for an orange wire w/ a black tracer (O/BL) instead. Does this help? If not, tell me specifically what you can and can not find. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

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05-01-2002, 12:32 AM	#1
Radon Registered Member Join Date: Sep 2000 Location: Calgary, Alberta, Canada Posts: 68	EFI to carb, fuel pump wiring question According to : http://www.jason.fletcher.net/tech/e...b/efi-carb.htm In order for the fuel pump to work, I need to make a few changes to the harness in the engine bay. "On the Black Harness: ----GROUND #97 (tan/light green - 18ga) to a suitable chassis ground. This creates the ground for the primary side of the fuel pump relay. ---Wire #361 (red 16ga) to #16 (the wire you ran to the ignition turn-on above). This creates the positive voltage supply for the primary side of the fuel pump relay." This is according to his 1990 Mustang, but doesn't seem to apply to my '87 as I don't have wires in those colors.. Does anyone know the color of the wires I'm looking for? Thanks. __________________ '87 Performance Red Notch Carb'd 306 w/ nitrous

05-01-2002, 08:03 PM	#3
Stang951 Registered Member Join Date: Apr 2001 Location: Metairie, La. USA Posts: 132	That is alot of freaking wires. I was thinking of doing the same thing, nut I am in no way sure of what can be ditched and what cant be ditched. Radon - I tried wiring the pump using different instructions and couldn't get it to work with the factory relay. I am about to rewire and try it this way. The main reason that I wanted to do it this way though was to keep the fuel pump cut-off switch. If you dont care about that you could wire it like Jeff Chambers did. __________________ Engine: 1990 5.8 / Edelbrock Performer set-up MSD ignition Suspension: Maximum Motorsports Caster-Camber Plates / Maximum Motorsports adjustable lower control arms / FRPP heavy duty upper control arms / Tokico Illumina Shocks and Struts / Ground Pounder Coil Over conversion kit front / Steeda cross brace sub-frame connectors / Drivetrain: Tremec 3550 trans / Steeda Tri-Ax shifter / Spec Stage II clutch and pressure plate / Spec aluminum flywheel / 5.8 in the hole