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Trailer Wiring Harness Installation - 2010 Toyota Highlander

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How to Install a Trailer Wiring Harness on a 2010 Toyota Highlander

Today on this 2010 Toyota Highlander we are going to be installing wiring harness part number 118449. The first thing I want to point out about our harness is that it comes in two separate pieces. We have got the first section which has an in line fuse in the modulite box as well as the port to plug in the vehicle. This is going to plug in underneath the dash on the driver side of the vehicle. The second part of the harness plugs into the rear of the vehicle inside the rear cargo compartment and that will finalize the tow package for us. We are going to start here inside the vehicle up underneath the dash and plug our first part of the harness in place. The port is located underneath the dash just left of the brake pedal taped to the main wiring harness. All we need to do in here is plug it in line and then we see on the back side of the modulite box we have got double sided tape. We want to find a good spot up in here and adhere the box to it. 00:54

Then we can take the provided zip ties and tie up the rest of the loose wires. With that part finished we can go to the back of the vehicle and plug in the second part in line. We are in the rear cargo area of the vehicle now and the second port that we are going to need to locate to plug our harness in line is located over on the driver side behind the storage panel over here. We are going to need to remove the rear cargo floor and fold up the forward one and also the driver side cover. To get the storage box out the screws at the bottom as well as the three push fasteners on the inboard side. One here, one here, and one here. Remove all of those. Then we can just pull it up and out of the way. With that pulled out of the way if you look just to the back side nearest to the tail light you can see there is a small 4 pin connector and that is what we are going to be plugging into. 02:03

The 4-pole end of the harness is intended to stay inside the vehicle. We want to look for a good route so we can put the cargo box back in and not damage the wires. We are going to take a zip tie and tie the line to this main harness back here and then we can run this wire out this groove right here. With that fed through we can put the storage box over on the driver side back into place. You can see with the compartment put back together that the 4-pole is going to rest nicely in this cargo compartment when not in use. When you want to use a harness just simply pull it out the back door. You can close the door on it. You do not have to worry about it being pinched. The weather stripping will prevent that from happening. You can put the flooring back together now and go to the final part of the harness. Go up under the hood now to the fuse block that we are going to be plugging our fuse into is located over on the driver side just right of the battery. I am going to remove the lid and each fuse position is labeled so you are looking for the one labeled towing the lid indicates a 30 amp fuse to be put in place. Our harness has a 10 amp max so that is why we are going to be using a 10 amp fuse instead. Take it and plug it into place. With that fuse in place our tow package is now active and our installation is complete. This will conclude the installation of wiring harness part number 118449 on this 2010 Toyota Highlander.

Info for this part was:

Employee Zack K
Video Edited:
Zack K
Employee Andrew K
Video Edited:
Andrew K
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Chris R
Video Edited:
Chris R
Employee Jeff D
Installed by:
Jeff D
Employee Cole B
Installed by:
Cole B
Employee Nicholas E
Test Fit:
Nicholas E
Employee Randy B
Test Fit:
Randy B
Employee Brent H
Test Fit:
Brent H
Employee Shane H
Test Fit:
Shane H
Employee Robert C
Test Fit:
Robert C
Employee Andrew L
Video by:
Andrew L
Employee Kathleen M
Video by:
Kathleen M
Employee Jonathan Y
Video by:
Jonathan Y
Employee Michael B
Video by:
Michael B

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