Fuel Injector Wire

[Will Williams]

My 2017 expedition has been running very rough. Or shall I say when I drive it, because of how it has been when I do drive it, I don’t drive it very much. So I check the codes on it. They came up as P0174, 0204, 0205, 0206, 0304, 0305, and 0300. While looking under the hood I found that the fuel injector wire on #4, 5, and 6 were either missing and or cut (most likely bitten off by “Rocky the Squirrel” and his friends). I brought a new replacement part(s), both wires are yellow. I have not pulled what is left of the wires in the vehicle yet, so I don’t know what color they are. But it looks like there are two wires for each injector, and they don’t look like the same color.

My question is, does it matter which wire goes to the repair part? I have attached pictures.

 

[Will Williams]

So Sorry the Wires are green in color.

 

[GlennSullivan]

Yeah, it does one wire is power and the other ground - see below. If it were me I would replace the injector connection harness, which plugs in with no patching or soldering, but if you want to patch in the new connectors I would determine by putting the old connectors up to the wire from the harness to determine which color belongs on which side and then match that "side" up to the proper side on the new connectors. I would also solder and shrink tube the wires to avoid then vibrating loose from a crimp connector in the future and causing you more pain.

Power Wire (12V):
This wire carries a 12-volt power supply from the engine's power system, usually when the engine is running or the key is in the "on" position.

Ground Wire (ECU Controlled):
This wire is connected to the ECU, which controls the fuel injector's operation by grounding the circuit to open and close the injector solenoid, thus controlling fuel delivery.

​

 

[Will Williams]

Glenn
Thanks for the help. For some reason I thought there was a reason for two wires. The problem is the three Motor craft replacement parts have the wire in the same color and the break is is too short for me to tell which is the ground and which is the hot. Replacing the harness.....next option.

 

[GlennSullivan]

Glenn
Thanks for the help. For some reason I thought there was a reason for two wires. The problem is the three Motor craft replacement parts have the wire in the same color and the break is is too short for me to tell which is the ground and which is the hot. Replacing the harness.....next option.

Maybe you could cut open the injector clip to see if you could expose the colors.

I have my 2017 with me and could take a look tomorrow to see what colors are in what positions if you want.

 

[Fastcar]

Might want to pull your engine cover to see if something set up housekeeping under it.

 

[twodollars]

I have not seen a standard port fuelinjector that was polarized, really shouldn't matter.

 

[Gary Waugh]

As 2dollars says, the injector leads are NOT polarity sensitive, that is why the wires are the same color, it doesn’t matter which way round they are connected.. the injector is just a magnetic solenoid, it needs 12 volts to open and allow the fuel to pass. The ECU just varies how long the solenoid is engaged, this controls the amount of fuel injected. Just make sure your connections are solid (use solder not crimp connections) or you will end up with a poorly running engine..

 

[Fastcar]

After reading all the previous comments, were it me, I'd opt for a new harness to remove all doubt down the road.

 

[Will Williams]

I went to a Ford dealership parts side to get a price for a harness. I was told that they don't make the harness for this model anymore.