2018 Honda Odyssey Trailer Wiring Harness Installation


In your video comparing your Expert Review Video of top 3 recommended trailer hitches for the 2018 Honda Odyssey https://www.etrailer.com/hitch-2018_Honda_Odyssey.htm, at 3:54 you show the Draw-Tite 76171 with the wiring harness coming from underneath/behind the bumper and attached to the mounting bracket with part 18144. However, all the wiring harnesses I have seen T-one 118781, Curt, etc show the wiring harness linking into the panel in the cargo area on the drivers side and then closing the rear door on it. How did you connect the wiring harness the way it is showed in the video so that it is permanently installed from underneath and not having to extend it out of the cargo area and shut the door on it? Is there a grommet port, etc? What wiring harness did you use in the video? Thanks!


Expert Reply:

With any 4-pole wiring setup the flat connector can be either routed outside the vehicle and permanently installed in a mounting bracket setup as with parts # 18144 and # 18136 or it can be left inside the vehicle so that it is not continuously exposed to the elements.

This is true for Tekonsha universal hardwire harness kit # 119147KIT that you referenced as well as for the custom-fit items made specifically for your 2018 Odyssey, which are shown on the linked page. These include 4-pole kits like # C56382 from Curt and # 118781 from Draw-Tite, which is the item you selected. Either of these custom parts will be easier to install than a hardwired kit like # 119147KIT since you do not need to cut into the vehicle's wiring.

For those that tow very frequently the external mount option is likely to be preferred for its handy access. But for occasional recreational towing we recommend keeping the 4-pole safely tucked inside the vehicle when not in use which protects it from moisture, dirt, salt and the potential for damage from road debris, such as rocks that might be kicked up as you drive.

There is no risk to the wiring from closing a rear hatch on it since the flexible gasket material around hatches provides more than adequate cushioning. Simply avoid the latching mechanism. The benefits to keeping the wiring tucked away except when in use include reduced risk of deterioration of the contact surfaces. Destructive corrosion may not always be obvious; even a slight whitish discoloration on the contacts can cause signal transmission issues.

Often owner's of a newer vehicle will prefer not to have to drill a hole or enlarge an existing grommet to route the wiring. I recommend keeping the harness inside the vehicle as shown in the linked video. For further protection of the connector I suggest an application of dielectric grease like # 11755.

expert reply by:
Adam R

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