Curt Class III 13256 on Canadian 2006 XLE Limited AWD (with pics)

[robaer]

Part IV - running the mains to the battery

I started in the back jack compartment. I hooked the 10/3 cable up inside the box and added a coil of blue 14 Guage wire for the line that will go into the cabin for the braking system to connect to. I fed this wire down through a rubber grommet in the bottom of the jack compartment. You can see it in pic 1 from underneath. This comes out just above and to the left of the tailpipe, so I snake it by the muffler hanger bracket, over the suspension coils and along the frame on the passenger side. You will note in the second picture that I used a couple of insulated brackets to secure the wire and the orangish goo is anti-corrosion gel to make sure rust wont set in to where I drilled the frame for the screws. Mostly I just zip tied the cable to existing brackets though... pretty easy.

Once at the engine compartment, I snaked the cable up into the engine following as close to the passenger compartment as possible. In the 5th pic you will see the blue brake wire has now been seperated from the black 10/3 cable so i can feed it into the passenger compartment at some point for the braking system. The 10/3 then snakes over the top of the engine by zip ties to an existing wiring harness that is hidden up inside the top area by the dash.

I dont have the circuit breakers installed yet, so I have just neatly tucked the cable around where it will eventually end up. The cb's will be mounted on angle bracket just to the upper left of the engine compartment... 3 of them. Two for the two 12v lines going back to power my relays and modulite and one for the brake system power that will be in the passenger compartment area at some point.

I got lucky... I bought 20 feet of 10/3 even though I estimated I would only need 15 feet to run the line. But I needed all 20 feet. There was non to spare. Also, the 10 guage wire and insulated jacket was fairly flexible... but if you just rung some 12 or 14 Guage you could save some time and hassle in doing the wiring and likely be no worse off. 10 Gauge is likely overkill... but it looks good.

In the back, I made sure I had about a 14 inches of cable inside the jack compartment so I could remove the trailer wiring box if I needed to do some work (ie replace a relay or something someday).

I also ran the wiring that is going to feed the modulite with signals, tail and stop lights. I basically did exactly what is shown in the e-trailer video for installing the wiring harness so I wont repeat that activity here. Same for attaching the 7 blade to the hitch and snaking those wires to the jack compartment... it went up through a grommet in the rear seat well and under the carpet to the compartment with ease.

[robaer]

Part V - Wiring up the harness and mounting the box into the jack compartment.

Here I show the wiring of the harness (from the 7 Blade) to the box. I used crimp connectors with male/female connections so I can remove the harness someday if needed. Easier than cutting wires and leaving not enough to work with next time.

In the first pic you can see where the 10/3 line and brake wire go through the rubber grommet in the bottom of this well. In the second pic you can see I removed the 2 bolts that hold the jack holder so that I had more room to stick my hands in there.

The design I chose actually didnt require removing the rear panel to get access...although that would have made bolting the box a bit easier. My hands got a couple of scratches trying to hold bolts and nuts in place as I tightened them... but there was just enough clearance for a small ratchet to fit in and tighten them down.

Pics 4, 5 and 6 show the finished product. The hose just above the box in pic 5 is drain hose from the compartment above. It just pulls out of the hole in the body and makes it easier to get your hands in there... and then it just inserts back into that hole. Toyota did a nice job of keeping water out of areas that it could pool... and it protects my circuit box too. In the 6th pic you can see the red and blue switches. The blue disables the center pin on the 7 blade (which is my reverse lights in this case) should I have a trailer that expects this AUX line to be something else. The Red switch disables the +12v relay so that I can manually cut off power if I dont want something running on the trailer from that line. Both are lighted switches (though very dim) and easy to reach without removing the jack.

The last 2 pics show the 7 Blade mounted to the curt hitch receiver... I think it looks great... tidy and easy to access. I also really like that multi connector as it gives both 4 and 7 wire out... most trailers just want the 4 and it saves me hauling a 7->4 adapter around.

[robaer]

Part VI - building and installing the housing for the circuit breakers

I was going to mount my 3 circuit breakers (40 Amp for +12V dedicated ACC line, 30 Amp for Modulite trailer lighting circuit and reverse light circuit and 20 Amp for the braking system which is yet to be bought) onto a piece of angle iron and bolt that somewhere in the engine compartment. On the weekend I planned to do this, I also happened to be repairing my outdoor plugs and had an idea. The 90 degree PVC housing/junction box was about the same width internally as the CB's I had. It was deep enough to house the 10 Gauge wiring and connections and long enough to hold 4 or 5 CB's along its length. I took it to the engine compartment and discovered that the place I wanted to mount the CB's (upper right corner just above the large fuse block) was too narrow to fit it in. BUT, I could cut and section the box to be just wide enough for the 3 CB's and rebond it together with PVC glue. I could also reduce the length of the goose neck openings (particularly since I only needed 1)... and I thought it would be fun too.

So... later in the week I set about doing just that. I ended up only putting the 2 CB's into the compartment that I need right now (ie left out the one for the brake system) because after building the box, I found a better solution for this. I happened to stumble across some ATC blade CB's (ie, they are similar to a normal car fuse but its a Circuit Breaker instead) and in looking on the web for a small fuse block I could use instead of my Frankenstein pvc thing (plus it would allow me to switch out a bad CB with even a fuse should I burn one out or something) I found the perfect little block. I likely wont get it for a couple of weeks but since the cable lengths and location wont change... I decided to go ahead and proceed with the original plan for now. Here's some pics.

I haven't connected the hot feed to the battery yet... want to test everything one last time and will just alligator clip it for the tests... and it was getting late... but the stuff is all mounted now.

[robaer]

Part VII - Final Chapter - hooking into rear ACC+ and reverse lights line.

So, with the mains powered up at the front and one line running through a relay at the back, the signals for right, stop, left, and tail lights connected to the modulite and the 7 blade wiring harness permanently attached, all that remained was to tap into a switched ACC source (so the modulite would operate when the key was in the ignition) and tap into the backup lighting circuit for that pin on the connector.

For the ACC+ I decided to use the driver rear corner panel connection for the 12V plug (aka "cigarette lighter plug"). I had noticed the 120V plug back there and mentioned this in earlier posts but had completely overlooked the round 12V plug which is only on when the key is on. Perfect.



That was an easy solution as it just meant running the wire from the rear left compartment, under the carpet and up behind the subwoofer. Popping off the rear panel was straight forward and very similar to what you see in the youtube videos for connecting to the drivers side lights. I had to pop more of the panel off (ie pulling it away from frame) so that I could reach the center wire on the plug and tap into that... but it pulled off freely and no plastic grommets broke.

To connect to the backup circuit, I mentioned that I was going to tap into the red with black strip wire that runs from the drivers side kick panel, along the drivers side door plates (front and back) and then into the rear quarter panel. When I removed the kickplate for the rear door (simple pry up and out maneuver with my fingers) I was pleasantly surprised to find the wiring harness had places where it was opened up and covered by clear accessable panels. This meant I could easily tap into the circuit under one of these access points and not have to open the harness and sort through wires.

I had to remove the rear door cable guide that covered the rearmost of these clear access panels (see pics below... easier to see than describe) and easily found the red with black stripe wire. I tapped into it with a T connector and did a quick test by using a circuit tester while the car was in reverse... all good.

Closed everything back up and my trailer harness was now completely wired.



Next project will include installing the brake system (already have the wire going from the rear of the van to the engine compartment... so mainly installing Circuit Breaker and brake system unit in cabin). I also would like to install bags in the coils to help support heavier trailer loads. Since my trailer needs right now do not require assisted braking or air bag support... I am leaving those 2 projects to maybe next year.

[mochrie71]

Hi Robaer,

I'm in the process of acquiring all the components for my 2007 Sienna to start towing. I am impressed with your set up....and would love to have something close to it on my Sienna. I am fairly ignorant when it comes to electronics and all your explanations, while in-depth, get my head spinning. I've narrowed down the parts I'm going to buy. I'm going to buy the Curt 13256 hitch, the wiring harness and the hopkins multi tow 7-pin/4-pin adapter. I guess my question is how is the Hopkins multi tow adapter mounted on the hitch frame? do I need to buy a housing box as well? Or is a clamp included in the kit? Thanks in advance for your help.

Chad Mochrie
Burbank, CA

[robaer]

Hi Chad

The kit came with an L bracket that you could mount to the hitch by either drilling screw holes and attaching directly, or by using a metal extender bracket and clamp (I have attached an example of the later). I dont believe the kit included the extender but it definately included the L bracket.

I didnt like the look of that and opted for a closed housing (image attached) which you can see more detail on through the following link
http://www.etrailer.com/p-18159.html
I really liked the look and its only 10 bucks (I found mine at a local Uhaul store actually so I saved shipping).

[robaer]

- UPDATE -
My modulite unit failed sometime in the past month. I noticed that my trailers left turn light was very very faint when signalling compared to the right... and the tail lights didnt come on when I turned on the vans lights anymore. I figured it was a ground problem (90% of all dim or failed lighting is related to poor grounding in my experience) but after tracing all the wiring in the trailer I found nothing obvious. I quickly rigged up a test kit with 2 old trailer lights I had in the basement.... and found they exhibited the same behaviour... so the trailer was not at fault.

I then started testing the connections on plug, various spots in the wiring and could see no problem.. so I reluctantly cut the modulite out and went down to my test bench. Sure enough.... powering just the modulite off a 12V source I was able to see the same problem with the test rig

I didn't originally buy the Modulite-HD and I didnt order from e-trailers as I had planned (found my old modulite at a U-haul center nearby) so I decided I should do what I had originally planned and ordered the modulite-HD from eTrailers. when it arrives I might replace my wiring box as well (its pretty crammed having now completed the job, I think I could simplify the wiring and make it look cleaner and less scary for people thinking about doing the same thing... plus I found a good electronics supply store in town with better hobby kit boxes I could use). Will post some pics when done.

[dutchin]

All FYI - for a 2011 XLE, the hitch installation process described above works perfect. Except for a plastic air dam that didn't exist in the Gen II Sienna's, this same hitch and its bolt locations works fine. See other threads for Gen III installation tips.