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Trailer Wiring Harness Installation- 2010 Ford Fusion

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How to Install a Trailer Wiring Harness on a 2010 Ford Fusion

Today on this 2010 Ford Fusion we are going to install part number 118422 from Tow Ready. The first thing we need to do is get inside the trunk area of the vehicle and remove some of the interior components. Go ahead and lift the floor and get it out of the way. Next, we need to remove the rear threshold right here. Remove the plastic rivets that hold everything in place. With everything loosened we can pull straight up on the threshold. It should pop loose. :41

We will go ahead and pull this panel out of the way. Then we will have easy access to our connectors right here. Next, go ahead and lay out our wire harness, our green wire is going to go over to the passenger side and our yellow wire is going to go over to the drivers side. We will start on the driver side, it will disconnect right here, then we will install the T-one harness in the same spot, it snaps in. Then the factory harness plugs into the T-One connector, notice they do not look alike, but they do fit together. 1:25

Now lets go find a spot for our modulite box. There is a piece of sheet metal in this well right here which will work fine. We will use our adhesive on the back to hold it in place. That will be good for now. Now we have the one wire with the ring terminal on it, we will attach it to the sheet metal right here. We will attach it right here, where it overlaps since there is plenty of sheet metal for the self tapping screw to dig into. We will leave this side alone for now and route our green wire back across to the other side. We will follow the factory wire harness and use a couple zip ties to hold everything in place. Back on the passenger side, we will do the same thing as before. The next thing we are going to deal with is our red wire coming from the modulite itself. We are going to be connecting up our black wire that is supplied with the kit. This wire will eventually be run to the battery. We are going to connect it using a butt connector, slide it on and crimp it in place. The other end will have our black wire. To run this up to the battery we have to exit the interior of the vehicle and go underneath and up front. This little round grommet here we can remove and punch a hole in that and run our wire through. I will put a little slit in the grommet, a cross. A regular pocket knife will work. We will poke our wire through, run our wire out the other side and reinstall our grommet. We will run that all the way up and run our wire out. Lets go ahead and reinstall our grommet. Then we will reassemble the interior components of the vehicle. With the 4-pole in mind, we will just push this off to the side and then reinstall the threshold. 3:51

Now we have easy access to our wire harness right here. We will leave that alone for now and go underneath the vehicle and run our black wire up to the front of the vehicle and to the battery. To run our wire, we went out the side of the interior component, rerouted it by the hitch, went to the center of the vehicle, went straight to the front, and threaded our wire above the heat shield and all the suspension components in the back. We worked our way around the gas tank, then threaded our wire inside the frame member leading up to the front of the vehicle. Now we need to pull our wire from the bottom, up to the top. The engine compartment is pretty packed on this vehicle, so we used some wire and made a hook out of it so we could grab the wire and pull it on out. The next thing we will do is route our wire were we want it, we will go around this reservoir here, around the battery, and connecting to this point right here. We are going to cut off what we want and add on our fuse holder. To this end we will add a butt connector. Next we will take our fuse holder right here and cut it in half. Add our ring terminal. Put on our ring terminal and reinstall the nut. Put the cover back into place. Our wire here we will zip tie into place where we want it, and add our fuse to our fuse holder. Now lets go to the back of the vehicle and test out our install. 6:22

To do our testing we will use an incandescent test light. We will take our ground clamp and clamp it to the white wire. Then we will go through the functions on our 4-pole. Our running lights first, thats the brown wire. Now our left turn signal, which is yellow. And then our right turn which would be green. Then our breaks which will be both our green and yellow wire. Looks like we are good to go. I will show you how to use the wire harness. To use the wire harness it is pretty simple. Pull out what you need to go out to the hitch or your trailer. Then go ahead and shut your trunk. This door seal is plenty thick so it will not hurt anything, just make sure you stay away from the latch. With the door closed you can still pull out what you need. That will finish our install of part number 118422 from Tow Ready.

Info for this part was:

Employee Joe V
Test Fit:
Joe V
Employee Nicholas E
Test Fit:
Nicholas E
Employee Alan C
Test Fit:
Alan C
Employee Zack K
Video Edited:
Zack K
Employee Andrew K
Video Edited:
Andrew K
Employee Joshua S
Video Edited:
Joshua S
Employee Chris R
Video Edited:
Chris R
Employee Jeff D
Installed by:
Jeff D

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