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Trailer Wiring Harness Installation - 2005 Jeep Grand Cherokee

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How to Install a Wiring Harness for a Trailer on a 2005 Jeep Grand Cherokee

Today on this 2005 Jeep Grand Cherokee we are going to be installing wiring harness part number 118394. Okay, we are at the rear of the Grand Cherokee here and we are going to go ahead and locate the ports that we are going to be plugging our wiring harness into. these ports are located directly behind the taillights on both sides of the vehicle. So, the first thing that we need to do is go ahead and remove both taillights. To do that, we need to remove the inboard screws that are holding it into place. There are two on each taillight. With those screws removed we can just kind of gently rock it back and forth to release the outboard side clips that are also holding the taillight into place. And with that pulled back, you can see on the back side of the taillight here is the port that we are going to need to disconnect and plug our harness in line to. And then for clarity, I am also going to remove this fasteners here at the bottom side of the wiring harness so I can set my taillight off to the side. 1:08

Alright, and starting over here on the driver side of the vehicle we are going to go ahead and start plugging our harness in line. The ports that we are going to be using on the driver side contain the yellow and brown wires on them. And before I connect this one to the taillight itself, I am going to go ahead and feed both the 4-pole end and and the passenger side harness through the opening in between the body and the bumper. And you will notice that the converter box that is built into the harness has double sided tape on the back side. So we want to go ahead and adhere that to the body component here. A good spot for that is just directly below the opening here for the taillight assembly on the body structure right back in here. Before I go ahead and adhere that to the body structure here, I want to go ahead and clean it off. 1:50

And then with the converter box adhered, we want to go ahead and take the white wire with the ring terminal on the end of it and ground it to the body component as well using the self guided screw that is provided with the installation kit. And with all of that done, we can go ahead and put the driver side taillight back on and we will continue underneath the vehicle where we will start routing our wires across. And now underneath the vehicle we want to go ahead and start routing our wires. We are going to take the 4-pole and just go ahead and route it to the center of the vehicle where I am going to tie it off here at the trailer hitch, using the fascia strap here on the backside of the bumper to kind of help hold the 4-pole in place for me. 2:27

And then we are going to take the passenger side connector, route it all of the way across and up through the same opening between the body and the bumper. Since the port is too big to wrap behind the same fascia strap, what we can actually do is remove these clips here that are attaching to the bottom of the cross member and pull those down. And we can actually route the wire behind there and use that to hold it in place. And we will just continue up to the passenger side connectors where we will go ahead and make our connections. With the passenger side taillight put back into place, our installation is essentially complete. And that will conclude the installation of wiring harness part number 118394 on a 2005 Jeep Grand Cherokee.



Is the Laredo the same?

David B.


Yup, the Laredo is the base trim package it won't change the way things are wired inside. If you have any other questions Pete let me know, I'll be here to help.

Info for this part was:

Employee Zack K
Video Edited:
Zack K
Employee Joshua S
Video by:
Joshua S
Employee Nicholas E
Test Fit:
Nicholas E
Employee Cole B
Installed by:
Cole B

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