Here's my little step by step of how I ran the power wire from the driver's side compartment in the back of the car to the battery in the engine bay.
First, easy enough, I removed the two trunk cargo panels and put them aside.
Then, I removed the two silver bolts (10 mm?) from the left and right cargo compartments and removed them by pulling up.
Then, I removed the five bolts (two normal, three for baby seats) (12 mm??) from the remaining cargo compartement at the top of the spare tire and removed the compartement.
Notice that I also removed the spare tire so I would have a lot of room to work in the area, but it's not needed.
Oh, and I shop-vac'd because there was a LOT of sand down there!
Then, I removed the driver's side compartment's panel to access the area where the module will be and the wire will start from. I attached the wire with a loop and electric tape on the top plastic part where the latch of the panel goes (1). Then, I ran the wire to the bottom left opening (2). Then, I pulled on the plastic panel that meets the floor of the trunk and tucked the wire under there (3) and out to the right opening (4). After this, I tucked the wire under the rest of the light grey plastic panel (this is where the shock absorber sits) and I worked the wire under the black plastic panel that meets the rear passenger door (5). I had the wire exit near the rear passenger's door latch, where the real rear wiring travels.
Before trying to run the wire behind the black plastic panel, I went to the rear passenger's door and pulled on the door sill and the black plastic panel in order to catch the wire as it gets close to coming out. The door sills in this car are super easy to remove, it is only lightly snaped, I had no worries of breaking anything. Just lightly pull the sill from the inside and towards you.
Note that this black plastic panel is insulated and makes it a little harder to run the wire under, but it's not a pain at all to achieve.
Note also that I didn't check if it was possible, but I probably could have ran the wire through the area where my head's shadow is, using the "fishing" technique (metal wiring, etc.).
So here you can see where my wire is coming out, close to the door latch. and under the black plastic panel that I pulled off without removing it. My wire is the one that sits in the white plastic clamp, coming from the left. (The other one in the clamp is the rear window tube for the windshield washer fluid.) It's really nice that those white clamps are there, it makes the job really clean, you have no worries when snaping the trims and panels back because you know the wire sits properly in place.
Here, you can see the rear passenger's door with its door sill removed and the black panel pulled back so I can access the car's body. I ran the wire all the way down from the latch, sitting the wire in all the available white plastic clamps for a clean job.
The next step was to run the wire behind the plastic panel that separates the rear and front door. I didn't want to remove this panel, I knew I could run the wire behind it. I went to the front door and removed the door sill so I could access the panel from both sides. To run the wire, I used a small diameter (but stiff) plastic stick as a "fishing line". I gently stucked the stick behind the panel, starting from the driver's door, until I could see the stick sticking out of the other side.
Then, I taped the wire to the stick with electric tape and pulled it back and voilà ! My wire was now ready for the next step.
Here, you can see the driver's door sill removed and the wire running along the existing wire harness that I followed from the back door.
The next step was to remove the "last" plastic panel, the one that meets the door sill. This plastic panel covers something I would call a "patch panel" (1). This is where many wires connect before continuing their way to the many parts of the car's electric system.
So, after I removed the plastic panel by pulling on it, I was able to see how I could route my wire.
I ran the wire under and behind this "patch panel" (1) and I ran it alondside the big wire harness (2). In order to have my wire hold in place, I attached it with a zip-tie (that you will be able to see on the next picture).
You can now see where I attached the wire to the big wire harness using a black zip-tie (1).
What I did next can't be shown on a picture. I simply routed my wire the best I could trying to follow the big wire harness up to the firewall, where it goes through a large rubber grommet to reach the engine bay (1). In order to help you locate it, it is just on the left of the silver metal pipes for the heater (2). Be careful, because even if the car was stopped for about an hour, those pipes were still hot! They carry prestone from the coolant system to the heater core (basically a radiator), in order to give you hot air in the winter.
So, in order to proceed, I moved the driver's seat all the way back, I raised the steering wheel as high as I could, and I layed on my back on the floor, working the wire the best I could, always trying to get my hands in the best position possible in between the pedals and metal parts up there. At times, it was a little pain to reach the wire, but not as the pain in the next step!
All you need to consider when routing the wire up there is to stay away from moving parts, in order not to have the wire damaged.
So I finally reached the manufacturer's large rubber grommet (1) that lets the wires through the firewall.
THIS IS THE WORST PART OF THE PROCESS! Everyone will agree.
You now need to find a way to get the wire through this rubber grommet!
What I did to get the wire through it was first to explore how I could get through it. I used a rounded-tip 4-inches nail (rounded it myself using a file) to see if I would at least get through between the metal and the rubber, but it was a bit too tight and unsecure to have the wire scrape onto the metal wall. So I opted to get through the RUBBER. The large wire harness goes through the very center of the rubber grommet, but there is a LOT of space around it. So I used a sharp-tiped 4-inches nail and I punctured a hole just above the wire harness, just where the rubber grommet forms a "ditch" towards the engine bay (3).
When you pierce your way through, you will get through a first layer of rubber, but there is a second one to pierce to reach the other side, into the engine bay... So get a nail that is long enough! I used a 4-inches nail (the type you use when building a wall structure in 2x4).
When I got the nail through the two layers of rubber, I went into the engine bay and located where it was coming from and marked the location. In order for you to locate the rubebr grommet from inside the engine bay, it is just behind the air filter box. You will see two rubber hoses (1) and your wire harness and rubber grommet are just a little higher and to the right (2) of those rubber hoses.
(In this picture, ignore the fact that my black wire is already through, I didn't took any pictures BEFORE running it through, so I had to use a picture of later in the process..!)
After marking the location of the puncture I had done, I went back into the car and removed the nail.
Then, I went back into the engine bay and used a long and thin flat screwdriver to check if I could get through the rubber grommet by the marked hole I just did with the nail. I had to work my way through, but I succeeded!
So knowing that I was able to get through, I knew I could again use the fishing technique to get my wire through! But the screwdriver AND the wire attached together were too THICK to get through and my wire got untaped from the screwdriver, so I had to use another technique.
I took brass metal wiring (the one that comes on a plastic spindle) that I tightly taped with electric tape onto my thin screwdriver. Be sure to properly cover the tip of the metal wire to be sure nothing gets stuck as you run the screwdriver through the rubber grommet. Also, I left the metal wire onto the whole spindle, to be sure I wouldn't run out of metal wire!
So I ran the taped screwdriver and metal wire through the rubber grommet into the hole I had marked and it worked! My metal wire was through, so I went back into the car and I untaped it from the screwdriver and I pulled the metal wire back two extra feet in order to be able to properly handle it.
Then, I took my wire and the metal wire and I attached them together. To be sure the metal wire wouldn't slip off my wire, I wrapped it around my wire for about 4 to 5 inches, in a spiral pattern, then I tightly taped them together, making sure again to propery cover the tip of my black wire.
(In this picture, you can see the metal wire and the black wire taped together, but you will be able to see just exactly how I wrapped the metal wire around the black wire in three pictures, when it's in the engine bay...)
Now that the black wire and the metal wire were tightly attached together, all I had to do now was to pull on the metal wire from inside the engine bay. So, I went back into the engine bay, removed the thin screwdriver that was still in place and started pulling. It got hard to pull when the junction of tape reached the rubber grommet, so instead of killing my fingers, I took the thin screwdriver and wraped the metal wire 3 times around its shaft to act as a handle. Now that I had extra pulling power, it went through! It felt like the rubber grommet was about to rip off the firewall, but don't be scared, the wire still got through with nothing ripping off!
Note that if you want to be sure it glides as it gets through the rubber grommer, you can lubricate the black wire before pulling on it. Use grease or water/silicone-based lubricant and it might make the pulling easier and less scary!
So here it is, my wire out of the rubber grommet in the engine bay still attached to the metal wire! The worst part is done! And the project of running the wire from the back to the engine bay is almost done!
Now you can remove the tape and unwind the metal wire from the black wire.
As mentionned earlier, you can now see how I wrapped the metal wire around the black wire!
Final steps! The wire has now reached the engine bay!
So all that's left to do now is to pull the black wire until there is no more loose wire inside the car (it's better to have someone pull on the wire while you check the remaining of wire left inside the car, in order not to pull too much!) and then route your wire to the battery, using zip-ties.
The route I took to get my wire to the battery isn't "straight to the battery". I like it clean, so I ran the wire cleanly.
I routed it from behind the brake fluid reservoir (pic. A),
then between the big wire harness (that runs to the car's computer) and the car's body (where the shock absorber is) (pic. B),
and then between the car's computer and the fuse box (pic. C).
Notice on picture "B" that I zip-tied the wire to the computer's bracket.
On my last picture (D), you can see the yellow fuse holder, which I zip-tied to the long screw (1) that holds the battery in place to the car's frame. On the same picture, I also zip-tied the black wire to a wire harness near "(2)".
Finally and obviously, the job isn't done as long as all the door sills, plastic panels and cargo compartments aren't put back into place, but you don't need a tutorial for this!
Now, you are ready to complete the rest of the installation with the T-One connectors and module (#118460). The worst part of the module's installation was to run the power wire to the battery, and it is now done!
I hope this tutorial will be helpful to someone, and that my explainations are clear and understandable. Sorry for the bad-ish quality of the photos, they were taken with my cell phone, which focus is really bad up close.
I ask a lot of questions on this forum, and I love to give back to the community by adding tutorials on how I did stuff myself, especially when I'm not the only one asking how to do them!
You can ask any questions and leave any comments, I will answer the best I can to help you!