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After searching and pouring through the inter-webs, reading argument and counter argument about installing a break controller, I decided to write a complete guide of my own. This guide is for Touaregs with the factory installed tow package. These, despite many rumors, do have the brake control wires pre-wired. Some cannot find it, but it is there. I installed the Tekonsha Prodigy P3 brake controller. First, find this little plug hidden in the bowels of your dashboard. Two size 20 star headed screws hold the cover in place under the driver’s dashboard. Once the screws are removed, pull down sharply toward the front. Two metal friction clips hold it in place. Pull down a few inches and undo the OBDII connection by squeezing the clips at the top and pulling up. Now pull the panel toward the driver’s seat. This will free the panel from the two clips toward the firewall. Open it up enough to unclip the foot light, then completely remove the panel. Now you have unfettered access to the wires you seek. Lay on the floor as best you can and look up. Follow the parking brake release cable. It should make almost a 180 degree bend. Look up from the apex of the bend, and against the outside wall. There is a grey foam thing sticking out of a black wire loom. This is your quest. Grab that grey foam and peel it back like an uncut…well, look inside. If at first you don’t succeed, pay a 14 year old boy a dollar to find it. It will take him 30 seconds. Trust me.
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Now you feel confident to order parts online. A few different sources offer the parts. I ordered mine from ECS Tuning. What parts you ask? Google “Tekonsha TB 0021” and read the instructions. It states 2005 to 2008, but it is verified accurate until (and including) 2014 models.
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The next step is to find a four pin 12 volt relay. This is because there is a constant voltage bleed through the red/black brake light wire on the Treg. This will cause a constant slight brake drag on your trailer…and decreased gas mileage! So the relay takes 12 volts to activate the controller. That’s as simple as I can say it, other than trust me. I found this relay at a local auto parts store. It also had the socket with four wires it plugs into. This made wiring it easy.
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To build the wiring harness, grab the harness from the brake controller, the relay and the plug for the Treg. The instructions walk you through the process fairly directly. What it doesn’t show you, is that you can draw power and ground via the black (2) and white (1) wires. This way the entire harness can be unplugged when not in use. Follow TB 0021 to the letter. Note that the ordered harness for the Touareg is numbered, as is the plug pre-wired in the truck. However, double check the wires going into the prewired plug, they have been known to be in the wrong order. I wrapped my bundle in friction tape for a cleaner look. Plug it in! Now look for a place to mount your controller.
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This is where things get interesting. I chose the far right side, as it seemed the least in the way. I moved the seat around and played with the location for quite a while. If you too choose this location, the mounting bolts become difficult to control. The screw on the right side of the metal to plastic isn’t accessible if the metal portion is mounted first. However, if the metal portion is mounted to the plastic clip first, you cannot access the screws to mount the entire piece. Rather than using the supplied screws, I used some leftover VW bolts and nuts. This works great if you don’t want the mount always there. However the nuts are a pain to get in place. Therefore, I added a bit of moleskin to the back of the metal bracket to prevent scarring of the dash. Yes, the dash that I just drilled holes it. Don’t mock me.
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Did this explain things? If you have any questions, I’ll do my best to answer. i did take other pictures, but I thought this was enough. I'd be glad to help anyone who wants to take this on.
Now you feel confident to order parts online. A few different sources offer the parts. I ordered mine from ECS Tuning. What parts you ask? Google “Tekonsha TB 0021” and read the instructions. It states 2005 to 2008, but it is verified accurate until (and including) 2014 models.
The next step is to find a four pin 12 volt relay. This is because there is a constant voltage bleed through the red/black brake light wire on the Treg. This will cause a constant slight brake drag on your trailer…and decreased gas mileage! So the relay takes 12 volts to activate the controller. That’s as simple as I can say it, other than trust me. I found this relay at a local auto parts store. It also had the socket with four wires it plugs into. This made wiring it easy.
To build the wiring harness, grab the harness from the brake controller, the relay and the plug for the Treg. The instructions walk you through the process fairly directly. What it doesn’t show you, is that you can draw power and ground via the black (2) and white (1) wires. This way the entire harness can be unplugged when not in use. Follow TB 0021 to the letter. Note that the ordered harness for the Touareg is numbered, as is the plug pre-wired in the truck. However, double check the wires going into the prewired plug, they have been known to be in the wrong order. I wrapped my bundle in friction tape for a cleaner look. Plug it in! Now look for a place to mount your controller.
This is where things get interesting. I chose the far right side, as it seemed the least in the way. I moved the seat around and played with the location for quite a while. If you too choose this location, the mounting bolts become difficult to control. The screw on the right side of the metal to plastic isn’t accessible if the metal portion is mounted first. However, if the metal portion is mounted to the plastic clip first, you cannot access the screws to mount the entire piece. Rather than using the supplied screws, I used some leftover VW bolts and nuts. This works great if you don’t want the mount always there. However the nuts are a pain to get in place. Therefore, I added a bit of moleskin to the back of the metal bracket to prevent scarring of the dash. Yes, the dash that I just drilled holes it. Don’t mock me.
Did this explain things? If you have any questions, I’ll do my best to answer. i did take other pictures, but I thought this was enough. I'd be glad to help anyone who wants to take this on.
