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The Highlander Towing Package includes a larger radiator and alternator, oil and transmission coolers and has a “prewired harness.” The wiring is a 4-way system: left stop & turn, right stop & turn, tail light and ground. This flat connector is good for smaller trailers, but since the new Highlander is rated for 5,000 pounds, a 6 or7-way system is needed. The 6-way adds electric brakes and a 12-volt source for charging a trailer battery. The 7-way adds an auxiliary feed often used for backup lights.

BTW, I’ll bet that all Highlanders come with a “prewired harness.” If anyone without the towing package can confirm this, then anyone wanting to tow a small, light trailer could order a HL without the towing package, saving about $200. All that would be needed is the hitch and converter/wiring harness.

Here is how I wired my Highlander for a 7-wire setup with a Prodigy brake controller. I’ll refer to wire color and gauge to make following along easier. And I’ll be using standard trailer wire colors. The hitch and wiring harness are Toyota.

Here’s what is needed:
a) 12 awg black power and 12 awg white ground from the controller to the battery
b) 12 awg blue wire from the controller to the connector.
c) 10 awg black power and 10 awg white ground from the battery to the connector
d) connect the controller’s red wire to the stoplight switch
e) mount the controller to the dash

The first problem was how to run the12 awg black and white wires the from the driver’s area to the battery and the 12 awg blue wire to the connector. There are no existing firewall penetrations that can be used and drilling a hole would not work due to the brake housing on the engine side of the firewall. Thanks to pbsled in his write-up on fog light installation (see postings 6 & 7 under Fog Light Diameter), the answer was the hood release cable. I first loosen the inter fender well shield. Then the 3 wires are pushed through the hood release cable grommet into the driver’s foot well for about a foot. The 12 awg black and white wires follow the hood release cable and come out just in front of the fuse box.

Also following the hood release cable are the 10 awg black and white wires that go from the battery to the connector.

These 2 sets of wires each have an auto-reset circuit breaker, 20 amp for the brake controller and 30 amp for the connector. I used a 1” wide aluminum flat bar to mount the 2 circuit breakers. The aluminum flat bar has a slight angle to follow the body contour and is attached using the fuse box bolt.


Back at the hood release cable grommet area, I joined the 10 awg black and white wires from the battery with the 12 awg blue brake controller wire. I encased these 3 wires in 3/8” plastic conduit all the way to the connector for added protection and easy of routing. The conduit goes down from the grommet area to under the chassis.


There are two plastic shields underneath (below the door openings). Removing the fasteners along the outer side will allow you to run the conduit towards the rear tire. The conduit will exit the plastic panel along side of a black with 2 white strips brake hose.


Run the conduit up and over the rear suspension toward the center. There is an unused 10mm stud at the top. A clamp holds the conduit from the suspension. Then the conduit is routed to left side to the stud used by the Toyota wire harness. The stud is near where the Toyota wire harness passed through a grommet from the interior. Then the conduit follows the Toyota wire harness to the connector.



I chose to use a multi-tow 4 to 7 way connector. This will allow using either the flat 4-way connector or the 7-way round connector. It is a sealed unit and also plugs into the Toyota plug. My only problem is the appearance of the connector – the way it hangs upsets the otherwise symmetrical shape of the Highlander. Oh well . . . .



The Toyota connector bracket was bolted to a tab located between the center and left side of the HL.


The brake controller red wire is connected to the brake stoplight switch. It is on the “cold” side with voltage only when the pedal is pushed. The switch is not too accessible. The easy way is to tap the Gray wire that plugs into the Toyota converter.

To mount the brake controller, the only good spot is below the auxiliary (spare change)
box. I used 2 well nuts to hold the pocket mount.


I did not hook up the backup lights as it I don’t feel they would be all at useful.

Overall, this was not too bad of a project. Only wish that Toyota had prewired the HL for a 6 & 7 wire systems as done on the 4-Runner, Tundra etc. Then it would have been a simple plug-and-play process.
 

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Discussion Starter #3
sumerwind, ended up with a Canon SD850 IS. Nice camera, now just have to learn all features.

The fascia is actually the black one that comes with the Toyota hitch. Now that I look at my pic of the rear, it does look like the color of the HL. I think I didn't set the camera correctly and also it was a little wet at the time. Maybe I should take another picture a little futher away to show the true colors.
 

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My only problem is the appearance of the connector – the way it hangs upsets the otherwise symmetrical shape of the Highlander.
Is there enough room that you could flip the connector over and have it on the top side of the mounting plate instead of the bottom? Obviously you'd have to cut a larger opening in the trim panel that comes with the stock hitch but that would move the connector up so it's even with the hitch instead of hanging down. It appears that the hitch bars are V-shaped in order to get around the spare tire and there could be enough room to mount the connector there. If there isn't enough room, how far out would the connector have to sit if you extended the mounting plate in order to make room?

I'm considering getting a non-OEM hitch that hangs below the bumper to avoid having the connector hanging down like that, but I much prefer the look of the Toyota hitch except for the placement of the 7-pin connector.

Excellent job on the pictures!

Aaron
 

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Discussion Starter #5
I did a quick measurement. With a made-up extension of maybe 1-1/2 inches and trimming the fascia panel it should work. With a made-up extension of about 2 inches no trimming of the fascia would be necessary. With either extension, the connector would be sticking out a little more than the "hitch" (I think the hitch is really called the receiver and the part with the ball that plugs into it is called the hitch).

The original mounting plate is welded to the bottom of the hitch tube so the connector and the wires behind it had to be in front of the tube. The tube is not V shaped, it's a slightly curve shape to it.

FWIW, the original Toyota 4 wire connector also mounts under. But it is a lot smaller and thus wouldn't stand out.

I'll try and take a few pictures and more accurate measurements and post on Sunday evening. The idea never entered my gray matter; if it's a doable, I'll do it. Thanks for the suggestion!
 

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Discussion Starter #6
Today, I unbolted the connector and turned it 180. It sticks out too far for me. The depth of the 7-pin connector, even allowing cutting the fascia, just makes it into a shin getter and a target for those who park by feel.
 

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Discussion Starter #9 (Edited)
nathanrobinson, no room. The hitch square tubing is just behind the fascia. As mentioned is another post, Toyota should have given us the 7-wire feature with the new 08 Highlanders as part of the tow package. With plug-and-play, the installation of a brake controller would have been super easy. And the connector integrated into the rear of the HL, not hanging out there.

If there are any Toyota employees out there reading this forum, add this feature to the Highlander. And while you are at it, how about adding electrically operated fold back outside mirrors to make getting through smaller garage door openings?

Saw a Honda Pilot with what appears to be an after market hitch. Its connector also hung down.
 

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Help! I'm trying to install the same 7-point trailer connector and a brake controller. I'm looking for a place to get my signal from the brake light switch. You talk about the gray wire that plugs into the Toyota converter - where do you mean?
Thanks!
 

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Discussion Starter #11
slik_mr2,

I used the Toyota trailer wire harness, part # PT219-48871. Included is the 4-pin wire harness that a trailer plugs into, miscellaneous hardware and the converter. It's the converter that is your key.

The converter is mouted upwards and to the left of the brake pedal on an exsisting stud. Near this location is a wire harness with a 10-pin plug that plugs into the conveter. (I assume this 10-pin plug and wire harness is part of the towing prep package option, but see my comments in my second paragraph).

The gray wire is part of this wire harness with the 10-pin plug. I just unwraped some of the black tape that makes up the wire harness and used a splice conector to attache the red brake controller wire.

Here is a quick snapshot of the converter.



Hope this helps you . . .
 

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Got it! Thanks. My '08 Highlander has the towing package and the converter is where you said. (Toyota could learn one thing from Nissan: my '05 Pathfinder with no option, came with factory hitch, trans cooler, etc, and totally plug-n-play wiring. I bought a 7-point harness from the dealer that plugged right-in in place of the standard 4-point, and a brake-controller harness that plugged right in under the dash. A dream! But the Nissan had other problems, hence my new HIghlander...)
 

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Discussion Starter #13
Glad it worked out for you slik_mr2. I agree with you, Toyota should have made this a simple plug-and-play setup. And I wish Toyota would have the outside mirrors electrically driven to fold back making getting into and out of tight spaces easier.
 

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Newsrv, what size splice connector did you use? From your picture (assuming the color codes are standard) it appears that you used a "red" 22-18 awg splice which looks about right for the grey wire from the converter box. The red brake controller wire from the Prodigy looks a little larger (maybe 18-14 awg range). Did you have any problem with the different wire sizes?

Sorry, probably a very noobish question. :confused:

I finally have (almost) all the parts assembled and I'll be hitting the garage with your steps printed out this weekend. :D

Aaron
 

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Discussion Starter #15
aaron_huber, the connector is red. I had a box of miscellaneous electrical connectors and found this one that would work (didn't know about any standard). The red Prodigy wire went into the connector without any problem. The gray wire was not a problem at all. To make it simple and give me more room, I unplugged the wire harness and unwrapped some of the black tape to give easy access to the gray wire. Hope this helps, it, not let me know.
 

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The Highlander Towing Package includes a larger radiator and alternator, oil and transmission coolers and has a “prewired harness.” The wiring is a 4-way system: left stop & turn, right stop & turn, tail light and ground. This flat connector is good for smaller trailers, but since the new Highlander is rated for 5,000 pounds, a 6 or7-way system is needed. The 6-way adds electric brakes and a 12-volt source for charging a trailer battery. The 7-way adds an auxiliary feed often used for backup lights.

BTW, I’ll bet that all Highlanders come with a “prewired harness.” If anyone without the towing package can confirm this, then anyone wanting to tow a small, light trailer could order a HL without the towing package, saving about $200. All that would be needed is the hitch and converter/wiring harness.

Here is how I wired my Highlander for a 7-wire setup with a Prodigy brake controller. I’ll refer to wire color and gauge to make following along easier. And I’ll be using standard trailer wire colors. The hitch and wiring harness are Toyota.

Here’s what is needed:
a) 12 awg black power and 12 awg white ground from the controller to the battery
b) 12 awg blue wire from the controller to the connector.
c) 10 awg black power and 10 awg white ground from the battery to the connector
d) connect the controller’s red wire to the stoplight switch
e) mount the controller to the dash

The first problem was how to run the12 awg black and white wires the from the driver’s area to the battery and the 12 awg blue wire to the connector. There are no existing firewall penetrations that can be used and drilling a hole would not work due to the brake housing on the engine side of the firewall. Thanks to pbsled in his write-up on fog light installation (see postings 6 & 7 under Fog Light Diameter), the answer was the hood release cable. I first loosen the inter fender well shield. Then the 3 wires are pushed through the hood release cable grommet into the driver’s foot well for about a foot. The 12 awg black and white wires follow the hood release cable and come out just in front of the fuse box.

Also following the hood release cable are the 10 awg black and white wires that go from the battery to the connector.

These 2 sets of wires each have an auto-reset circuit breaker, 20 amp for the brake controller and 30 amp for the connector. I used a 1” wide aluminum flat bar to mount the 2 circuit breakers. The aluminum flat bar has a slight angle to follow the body contour and is attached using the fuse box bolt.


Back at the hood release cable grommet area, I joined the 10 awg black and white wires from the battery with the 12 awg blue brake controller wire. I encased these 3 wires in 3/8” plastic conduit all the way to the connector for added protection and easy of routing. The conduit goes down from the grommet area to under the chassis.


There are two plastic shields underneath (below the door openings). Removing the fasteners along the outer side will allow you to run the conduit towards the rear tire. The conduit will exit the plastic panel along side of a black with 2 white strips brake hose.


Run the conduit up and over the rear suspension toward the center. There is an unused 10mm stud at the top. A clamp holds the conduit from the suspension. Then the conduit is routed to left side to the stud used by the Toyota wire harness. The stud is near where the Toyota wire harness passed through a grommet from the interior. Then the conduit follows the Toyota wire harness to the connector.



I chose to use a multi-tow 4 to 7 way connector. This will allow using either the flat 4-way connector or the 7-way round connector. It is a sealed unit and also plugs into the Toyota plug. My only problem is the appearance of the connector – the way it hangs upsets the otherwise symmetrical shape of the Highlander. Oh well . . . .



The Toyota connector bracket was bolted to a tab located between the center and left side of the HL.


The brake controller red wire is connected to the brake stoplight switch. It is on the “cold” side with voltage only when the pedal is pushed. The switch is not too accessible. The easy way is to tap the Gray wire that plugs into the Toyota converter.

To mount the brake controller, the only good spot is below the auxiliary (spare change)
box. I used 2 well nuts to hold the pocket mount.


I did not hook up the backup lights as it I don’t feel they would be all at useful.

Overall, this was not too bad of a project. Only wish that Toyota had prewired the HL for a 6 & 7 wire systems as done on the 4-Runner, Tundra etc. Then it would have been a simple plug-and-play process.
 

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Very much appreciate your detailed presentation. I ordered my parts from E-Trailer and followed their installation directions. Wondered why you brought the ground from the connector back to the battery?
 

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Discussion Starter #18
One could run a ground wire from the connector to a nearby body stud/bolt. However, a direct connection to the battery, using heavier gauge wire, will prevent problems (pardon the pun) down the road. Since you have to run the power wire from the battery to the connector, it’s a simple matter of adding the ground wire to the installation and avoid potential trouble.

If you use the Prodigy brake controller, be sure to run its ground directly to the battery.
 
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