DIY Electric Brake Controller Installation

MoonDawg · 11-14-2007, 08:12 PM

I have a Toyota hitch with standard 4 wire flat connector and now I want to add a 7 pin RV connector and brake controller so that I can pull a trailer with electric brakes. I do not want to splice into the brake light switch to obtain the stop signal to the controller for fear that Toyota will void my warranty.

Q1: Is the brake light signal available on an unused connector under the FJ dash?

Q2: How have others routed the cables to the rear?

Q3: Where did others mount circuit breakers for the Aux Power to trailer and power to the brake controller?

Planned Installation:

I am using a Hopkins #47185 4 wire flat to 7 blade RV connector. I have drilled a hole in the mounting bracket and placed it just behind the Toyota OEM connector using the same bolt. it hangs down a bit further than the receiver but not that much to be a problem. I connected the white (ground wire) to the other end of the Toyota mounting bracket that bolts to the frame and that provided a very good ground.

The three wires with yellow crimp connectors are the wires that need to be added. One wire is Blue (brake signal from controller), one Black (12V aux power) and the other Purple (backup lamps).

The pinout on the 7 blade connector is as follows:
1:00 - Aux Power (Black)
3:00 - Right Turn (Green)
5:00 - Electric Brakes (Blue)
7:00 - Ground (White)
9:00 - Left Turn (Yellow)
11:00 - Tail (Brown)
Ctr - Reverse (Purple)

The pinout on the four wire flat connector (from top to bottom)
Right Turn - (Green)
Left Turn - (Yellow)
Tail - (Brown)
Ground - (bare pin)

I plan to use a Tekonsha Prodigy brake controller. Mainly because They have posted the wiring diagram and the unit was recommended by a boat dealer that installs these things regularly. My only problem is getting a brake signal for the red wire to the controller without splicing into the vehicle wiring harness.

I plan to use a 25 amp thermal circuit breaker from the battery to the brake controller (black) and a 40 amp thermal circuit breaker from the battery to the Aux Power (black) to trailer. I will probably use something like the Blue Sea Systems 185-Series Thermal Circuit breaker because they are surface mount, Ignition protected and weather resistant. They will most likely be mounted in the engine compartment so those are nice safety features. These breakers are readably available at most marine stores.

MoonDawg · 11-16-2007, 02:47 PM

I have found part of the answer in the documentation for the wire harness. It looks like I need to find a way to connect to pin 8 of the tail lamp converter or find someway to attach to the ground side of the brake switch.

Decidion · 11-17-2007, 04:27 AM

Unfortunately, I can't help with any of your questions because I had my RV dealer do the installation of my Prodigy, however I do have one helpful hint. Unless you mount your controller on top of the dash, there isn't a whole lot of places you can put it and still keep it in operational position tolerance (facing forward at a max of 70 degrees (? I believe it's 70, maybe it's less) tilt.

I didn't want to mount it to the dash because most of the time it isn't being used and no need to have this unused bracket permanently mounted there...nor did I just want to leave it up there to temp thieves.

So what I did was to mount it directly to the fuse cover, routing the cable through the internal fuse area just in front of the drivers left knee. I bought a second fuse cover to keep in place when not using the controller, then when I need to tow the RV, I just pop off the fuse cover and pull out the controller cable. The I get the original fuse cover (with the prodigy bracket mounted to it), route the cable through the hole in the cover and then plug it into the Prodigy and snap the cover into place. Nice, neat, out of the way, easy to access, not noticeable to thieves, and if it isn't being used, you would never know I had a brake controller installed.

I can post pics if your interested.

MaineFJ · 11-17-2007, 07:43 AM

pics, please - i may need to do this upgrade for spring - I've already learned a lot from this thread - a few pics would help clarify for my feeble mind -

thanks!

Decidion · 11-18-2007, 12:57 AM

Ok, here is how I mounted the brake controller...

First picture shows what it looks like most of the time with the spare cover installed.

Second picture, I removed the cover and pulled out the connector the RV deal installed.

Third, I route the connector through the hole in the original fuse box cover that has the Prodigy brake controller bracket mounted to it.

Fourth, I plug the connector into the Prodigy and slide it into the bracket.

Fifth, I snap the cover back in place.

Even with the weight of the brake controller, the cover stays in place and won't pop loose unless I make it. Overall it works great. When I'm done towing, I just reverse the step and keep the controller in the house.

Decidion · 11-18-2007, 01:11 AM

Here are some more pictures....

First picture is what the controller looks like from the drivers seat when in place.

Second picture shows how the RV dealer mounted the connection block to the top of the drivers side wheel well in the engine compartment. The power wire comes directly off of the positive terminal of the battery, then goes to an inline fuse and then to a three way connection block. The other two leads off the connection block go to 1) the brake controller and 2) the AUX power of the 7 pin connector in back (to charge the RV battery).

The third picture shows the connection block in the engine compartment again and where the pass through into the cabin is for power to the brake controller.

The fourth picture shows the 7 pin connector mounted to the bracket that the original 4 pin connector was mounted to. I don't have the snazzy dual connector like MoonDawg has pictured, but now that I know they make those I may go and get one. I just zip tied the 4 pin connector out of the way in case I ever need that type. Sorry for the mud...I was out wheelin'

The wiring all gets routed under the vehicle, tucked away and zip tied up along the frame and other components. I preferred them doing it this way, because if I ever have to change or replace anything, I don't have to tear apart any interior molding or anything. It is far enough out of the way that I am not worried about brush or rocks, except with the 7 pin connector....and I don't know where you could put that and not have it in the way. I guess you could build some kind of customer bumper attachment or something, but that was far more work.

As far as tapping into the brake circuit, the dealer tapped directly into the brake wiring in the back. They popped out the tail light access cover and accessed the wiring there.

MoonDawg · 11-18-2007, 09:45 AM

Thanks for posting the pics Decidion!

It really helps to see how others have accomplished the installation.

You brought up a point that I never thought about and that is the angle of the brake controller. It makes sense that since the controller is determining acceleration that it would work best if it is mounted horizontally. There is certainly a shortage of horizontal mounting places in the cab of the FJ. It is great to know that the controller will work at the angle yours is mounted at.

Sensing the signal at the brake light seems cheesy but that is the only way I can think of to keep the vehicle wiring intact. It is good to know that that is how the pros do it as well.

Cruiser Clint · 11-24-2007, 03:54 PM

Would this type of brake control harness work? eBay Motors: Prodigy Brake Control Wiring Toyota & Lexus Vehicles (item 110195164940 end time Nov-28-07 04:24:27 PST)

MoonDawg · 11-26-2007, 04:17 PM

Hey Cruiser Clint... thanks for sending that link! Life would be great if Toyota had included a connector like that under the FJ dash. So far I have not found one and nobody has talked about having used one for their installation. I am certainly going to look again now that I know the shape of what to look for.

N22285 connector pinout

MoonDawg · 11-26-2007, 04:59 PM

Unfortunately I did not find a brake controller connector

I have included some pictures of what I found. The first is the Tail light converter wiring connector (plugged into the blue housing). The second is the stoplight switch (at the brake pedal). I wish I knew the manufacture and part number of the connectors. I could buy matching connectors and tap into the brake signal at one of the connectors.