Never understood why Toyota decided to mount the trailer plug where they did, what were they thinking????? Having to add a plug extension in order to hook up any trailer is kind of ridicules, don’t you think?
Fist time hooking trailer to truck I realized this was going to be a problem, having to kneel down to plug in harness was going to be a pain in the arss, especially in the rain or on a dirt parking lot or road. As many here have pointed out, extension harnesses are available, but I wasn’t keen on routing/looping extension harness closer to tongue. For me, it would look like crap (most important…..lol), with a possibly of dragging harness while towing, loosing trailer lights, and brake functions.
After lying on my back, staring at Toyota’s 7/4 pin plug to formulate a plan, to my surprise, they use the same connector as the newer OEM Ford & Chevy trailer plugs. Yes, the factory wiring harness just unplugs from the back of 7/4 housing. At that point I unbolted the factory trailer plug from frame, unclipped harness retainer clips, and unplugged the two gray factory plugs to remove from vehicle (very easy to do).
Took the harness down to the local auto parts store to see what I could match up. Low and behold found the perfect plug, Hopkins Endurance 7 RV OEM Replacement Plug part #40940. Then test fit my harness to the new plug, perfect fit! Then found a mounting bracket, Hopkins 7 RV Blade Bracket part #48615.
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Next, it was time to extend factory harness, untapped and opened wire loom to expose wires. Then proceeded to cut wires (recommend staggering cuts every 1” or so to prevent adding extra bulk to the harness), then spliced extension wires (roughly 12-15” in length) with solder and heat shrink tubing to prevent corrosion as [MENTION=85467]BobsTrail[/MENTION] mentioned. Remember to use same gauge wires with same color whenever possible. Rewrapped harness in loom, added some additional loom to cover extension, then retaped, looks factory.
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Time to position new bracket, it’s a tight fit with my spare (285x70x17 Nitto), but I was able to place it so cover would open high enough to allow trailer plug to slide in/out easily. Also needed to check that receiver lock was able to insert and remove without hitting plug cover. I was able to achieve this without having to cut the bumper cover! Marked bracket mounting holes, drilled two holes, installed screws, and then installed new plug. Added die electric grease to all three connectors, inserted harness into 7 pin trailer plug, routed harness (following how the factory harness was initially run) back to two gray factory connectors, then tied harness to frame with wire ties……looks factory.
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Then tested each pin at the 7 pin plug with a volt meter to verify proper operation i.e. left turn, right turn, parking light, brake output, and ground. Everything confirmed correct. Time to connect trailer, all functions worked properly. Cost for plug and bracket was around $25 ($18.38 with free Prime shipping
Amazon.com: Hopkins 40940 Endurance Quick-Install 7-Blade Connector: Automotive), I had wire and loom, and about an hour of my time once I figured it out. It’s worked out awesome, if it’s raining when hooking up trailer, just open the tailgate and be shielded from getting wet. And no more getting under vehicle to plug in a damn harness, Toyota take note, this is how it should be!
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Good luck which ever way you decide to go!