FPDM Harness



Build Your Own Dual FPDM Harness		Install Summary
This article walks through the steps on how to build your own Dual FPDM Harness for your 2003/2004 Cobra or really any Mustang with a Returnless fuel system that wants the capacity to run dual Ford GT pumps. Before I get started I wanted to give credit where credit is due. This is the site I based my build off of http://www.innovativesitedesign.com/03cobratech/gt40pumpupgrade.html and has some great FAQ info about why this modification should be done when running dual GT pumps. As well as 04sleeper for passing it on to me and answering questions. The article here is just concentrating on the harness assembly and to clarify a few things that weren't 100% clear. For the harness plug ends you really have two options. First is to hit the local scrap yard and look for any 99+ Mustangs (V6, GT, Cobra) for FPDM plug ends. They are quite easy to find and you get to work with the proper wire colors for this build. If you can't find them or don't have the time you can buy them from Ford for $25-30 each, Ford Part # 3U2Z-14S411-SAA. I went with 40 amp relays for this harness but you could get away with something a little less. Something else to think about is some type of plug end for the wires going to the fuel pumps and the 8 gauge wire going to the fuse box. Napa sells a connector that screws together from both ends and they make it for 8 and 12 gauge wire. This allows you to disconnect the harness at the fuel pump so you can drop the tank instead of cutting and soldering the wires back together or so you can disconnect the main power wire while doing work on the system. FPDM Plugs The Grey/Pink stripe wire from the FPDM plug and solder 10 feet of Red 12ga wire to it as close to the plug end as you can and cover in heat shrink. Repeat on second FPDM plug. If using the Ford plug with all black wires refer to Figure 1 on the right for the corresponding wire colors. These are your Positive + wires for your fuel pumps. The Red/Black stripe wire from the FPDM plug and solder 10 feet of Black 12ga wire to it as close to the plug end as you can and cover in heat shrink. Repeat on second FPDM plug. These are your Ground - wires for your fuel pumps. The White/Red stripe wire from both FPDM plugs will be combined and soldered to the amp bypass. Tape or zip tie these wires together till we are ready to cover the bypass plug. Only one of the Light Blue/Orange stripe wires is needed so on one plug end tape it off and on the other you can either cut it short and cap it off or if you are experienced with taking apart the plug ends you can remove that pin all together. The remaining LB/O wire will go to the bypass plug. The Black wire from each FPDM plug should be combined with the ground wires from the two relays, soldered together and grounded in one location. The Pink/Black stripe or Dark Green/Yellow stripe wire from the FPDM plug will go to the 12V "Output" from one relay. Crimp on or solder a female terminal connector. Repeat on second FPDM plug and connect to the other relay. Amp Bypass Plug in the amp bypass to one of the FPDM plug ends. There are three wires you will need on the amp bypass the rest can be cut and capped or the pins removed. One of the wires that you will need does not have a corresponding wire in the pin location so the plug has to be disassembled and a wire moved into that location. Mark wires you need (see Figure 2). There is a locking clip that can be pushed out from the back side of the amp bypass use the pick or other narrow tool to push this out (see Figure 3). From the front side of the plug use the same tool to release the individual clip holding in each pin and pull the wire out from the back of the plug. Be careful as it is easy to break the clip from pulling on the wire too hard. I removed all wires except for the two that were needed then took of wires I removed and push it into the back of the plug for the third wire that is needed. Take the corresponding wire from the back of the amp bypass for the Light Blue/Orange stripe wire and solder it to the one Light Blue/Orange stripe wire from the FPDM harness cover in heat shrink. Take the corresponding wire from the back of the amp bypass for the White/Red stripe wire and solder it to the two White/Red stripe wires from the FPDM harnesses and cover in heat shrink. Take the corresponding wire from the back of the amp bypass for the Pink/Black stripe or Dark Green/Yellow stripe wire and solder on two short lengths of 16 gauge wire and cover in heat shrink. Crimp or solder on two female terminal connectors. These two wires will go to the switch side of each relay. Relays Run approximately an 8-10" length of 16ga wire from the relay Ground (length varies depending on where you will mount your relays and where you ground the harness) to the Ground wires from the FPDM harness plugs. Repeat on other relay then combine all four and solder. Crimp on a ring terminal so it can be grounded to the chassis. Run the 8ga wire you got in your amp install kit from your engine compartment to the back corner of the car where the FPDM are mounted. There are different ways to connect this to your electrical system. I choose to use the fuse holder that came with the amp kit and connecting to the fuse box under the hood or you can go directly to the positive terminal on the battery. Do not connect it to electrical system yet just run the wire. If you got fuse holders that came with 12ga wire add a female terminal connector to one end and plug it into the 12v "In" side of one relay. Repeat on the other fuse holder for the other relay. Connect/solder both fuse holders to the 8ga wire you just ran from the fuse box/battery. Plug in one of the corresponding Pink/Black stripe or Dark Green/Yellow stripe wires from the amp bypass (step 6 under amp bypass) into the "switch" side of the relay. Repeat for other wire and relay. Summary The harness is now complete and ready to install in the car. Everything at this point should be pretty self explanatory, the combined ground wire should go to the chassis, the 12V "In" wires connect to the 8 ga wire from the engine compartment, the 12ga Positive and Ground wires from the FPDM plug go to your fuel pumps, the two FPDM plug ends go to the each FPDM (obviously you have to add a second one), the bypass plug connects to the factory FPDM plug end and the relays get mounted wherever it is most convenient for you. FPDM Harness Plug 1 Black - Combines with other Ground wires and grounds to chassis. Grey/Pink stripe - 1st Fuel Pump + Red/Black stripe - 1st Fuel Pump Ground - White/Red stripe - combine with white/red stripe wire and connect to amp bypass Light Blue/Orange stripe - connects to amp bypass Pink/Black stripe (or Dark Green/Yellow stripe) - goes to 12V "Output" from relay 1 FPDM Harness Plug 2 Black - Combines with other Ground wires and grounds to chassis. Grey/Pink stripe - 2nd Fuel Pump + Red/Black stripe - 2nd Fuel Pump Ground - White/Red stripe - combine with white/red stripe wire and connect to amp bypass Light Blue/Orange stripe - not needed, cut or remove pin from plug Pink/Black stripe (or Dark Green/Yellow stripe) - goes to 12V "Output" from relay 2 Amp Bypass Light Blue/Orange stripe - connects to corresponding wire from FPDM Harness Plug 1 White/Red stripe - connects to corresponding wires from both FPDM Harnesses Pink/Black stripe (or Dark Green/Yellow stripe) - split this wire into two wires and connect to the "switch" side of both relays Relays Ground - combine both with Black ground wires from FPDM Harnesses and ground to chassis. 12V In - connects to inline fuse and combined and connected to 8ga wire from fuse box or battery 12V Out - connects to Pink/Black stripe (or Dark Green/Yellow stripe) wire for each FPDM Harness Plug Switch - connects to the corresponding Pink/Black stripe (or Dark Green/Yellow stripe) wire from the Amp Bypass For any questions regarding this tech article please visit our forums at www.modularrevolution.com/forums/forums.php		Written by: Bill Putnam Product Manufacturer: NA Difficulty Level: Time: 1.5 - 2 Hours Tools: Wire cutters, wire strippers/crimpers, soldiering iron, lighter, dental pick or other long narrow pick. Parts: (2) FPDM Plug Ends (Ford part# 3U2Z-14S411-SAA) (2) Relays (1) Mach 460 Amp Bypass Plug (1) 20 Feet of Red 12ga Wire (1) 20 Feet of Black 12ga Wire (1) Amp Install Kit w/8ga Wire (2) 12ga fuse holders and 15amp fuses (1) 12ga ring terminal (8) Female terminal connectors Solder Heat shrink

		Pictures
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