If you already have the 7 pin connector on the rear go buy a controller and follow the instructions, I recommend the Tenkonsha Prodigy, works great and the instructions are excellent, you'll have it done in no time if you're electrically inclined with your vehicles. For a 2005 I suspect it'll be super easy
If you have a 4 pin connector (like I had on my 2002) you have a bit of work. Locally I was quoted $800 CAD including the Prodigy controller. I spent a few hours running in the required wires, charge line to battery on a auto reset breaker, brake line from controller. I basically bought the controller then researched on this forum what else I needed to connect other than the existing 4 wires. Ran new wires along driver's side interior and dropped the new wires down through the waterproof boot to the exterior along with existisng wires. To do this I pulled out all the driver's side interior panels. I also cut off the 4 pin connector, put on the 7 pin with a custom bracket in the old 4 pin location. The install took me about 4 hours but the result looks factory even underneath the interior panels.
how do i install electric brakes on my 2005 sequoia sr5? anyone knows?
Linear Mode
