bing tracking image

Trailer Brake Controller Installation - 2004 Toyota 4Runner

Customers compare 3040-P to these similar products

Products Featured in this Video

How to Install a Trailer Brake Controller with Wiring on a 2004 Toyota 4Runner

Today on this 2004 Toyota 4Runner we are going to be installing Prodigy brake controller along with the Prodigy wiring harness part number 90185-3040P. The first thing we want to check for in this vehicle just to make sure that the vehicle is fully equipped with the tow package and that it will have the port that we will be plugging into. A good way to check that is to come to the rear of the vehicle and make sure it has a factory installed 7-pole and not just an after market one. With that verified we can go inside the vehicle and start locating the wiring port that we are going to be plugging our brake controller into. 00:31

The port that we are going to be plugging into is located over on the driver side of the vehicle just left of the emergency brake pedal. Just above the plastic molding we can probably access the plug without removing anything however there is a ground wire on our harness that we are going to need to attach to a grounding stud. To access that we are going to need to remove a couple of pieces of molding. We need to remove the kick plate cover and then the full plastic molding over on the driver side. Now that we have got the paneling removed we can take and plug our harness in place. You can see right here is the port that we are going to be plugging our harness into. 01:09

If you follow down the harness you can see we have got a loose white wire that needs to be grounded. I do not see a common grounding stud in here however there are multiple bolts that we can use as attaching points for our ground. I think we are going to use this one right here since it is somewhere close to where our harness is located. We have got the other end of the plug here and that is going to plug into the backside of our Prodigy harness. Next we need to figure out where we want to mount the Prodigy at. It is always a good idea that you mount it in a aerial. It can be easily accessed by hand in case you need to adjust or for even for emergency braking situations. You also do not want to be in a spot where it is going to interfere with your everyday driving. On this particular vehicle unfortunately there is not a whole lot of excess room in the dash area. I think we are going to mount it somewhere right in this area here. When you are mounting the Prodigy it needs to be mounted in a straight line for the braking of the vehicle. It can not be turned to the right or left either way. Note that the Prodigy controller comes with two different mounting brackets. We have got the more traditional bracket that mounts to the Prodigy using two screws on the side which is a little bit smaller but it is a little more permanent as well. We have also got the mounting pocket which is a little bit more bulky but would allow you to easily remove the Prodigy when not in use or if you want to switch it from vehicle to vehicle. 02:34

Instead of having mounting screws on the sides it has got clips to hold the Prodigy in place. Since we are a little short on room in this vehicle we are going to use a smaller mounting bracket for our installation today. We are going to line it up and start drilling out the holes that we are going to use for the mounting. Before drilling the mounting holes you want to make sure that there is nothing behind the dashboard that you may drill in to that may damage the vehicle. When choosing a mounting location you need to take into consideration that if you are using the smaller bracket you are going to need to put in a new mounting screw in the side so you need to make sure you give yourself enough room. Next we will take our Prodigy controller and mount it into position. To provide a little bit more clearance I am going to use the upper mounting holes in the bracket. Next with our controller mounted we can just take our wiring harness and route it across over to the Prodigy where we are going to plug it in. You can see instantly with it plugged in we have got NC flashing on our Prodigy brake controller. That is indicating that we do not have a connection to a trailer. That will blink a few times and then it will go to two dots. If you have any loose hanging wires left over from our connection you want to secure those up and out of the way. Then we can start to reinstalling the interior of the vehicle. Now that we have got the interior reinstalled we are going to plug our trailer in to our 7-pole at the rear. You will see that when we do that we have a C on the display screen of our Prodigy that is showing that we now have a connection. Now when we hit our brake pedal we get digital read out on the screen that lowers when you use the slide bar. With that, that will conclude the installation of Prodigy brake controller part number 90185-3040P on a 2004 Toyota 4Runner.



Thank you for the helpful video. Do I need to buy and install a brake controller if I am towing a 1977 Rancho el rae 18ft travel trailer?

Etrailer Expert

Chris R.


If the trailer is equipped with electric brakes, you'll need to add a brake controller to power and control them. If not - there's no need for a brake controller. The Tekonsha Prodigy P2 # 90885 highlighted in the video will work great.

Info for this part was:

Employee Zack K
Video Edited:
Zack K
Employee Andrew L
Video Edited:
Andrew L
Employee Dustin K
Video Edited:
Dustin K
Employee Sue W
Video Edited:
Sue W
Employee Jeff D
Installed by:
Jeff D

At we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.

About Us
photos and videos
Original Photos & Videos

Produced to make sure you know what you are getting and you get exactly what you need.

Installations Completed

To make sure products work and fit the way they are supposed to.

etrailer call center
Phone Calls & Emails Answered

1,125,924 phone calls and 1,350,587 emails to help find the right solution.

etrailer training
Average Hours of Product Training

We get to know our products firsthand so experts can better help you.

etrailer service
Years of Quality Customer Service

Assisting our neighbors and customers, face to face at the counter.

etrailer experts
Pages of Expert Information

Created to make sure you have all the answers to your questions, from real experts.