4Runner Electric Brake Wiring Issue

I went to UHaul to have professionals wire a Prodigy 2 Brake Controller. My 2016 4 Runner came with a Toyota pigtail and a connector but I decided that to be sure its was connected properly I’d have an expert do it.

Unfortunately there is something amiss. With the Prodigy in place, when I turn on my headlights the slip indicator idiot light goes on, the ABS warning light goes on and the brake lights go on. The brakes are not actually on, however. I find it hard to believe that UHaul did it wrong but when I disconnect the brake controller all goes back to normal.

Prodigy provides this generic wiring plan/instructions.

BLACK wire carries 12V power and connects to the vehicle + battery post through a 20- or 30-amp circuit breaker like # PK54220PL or # PK54530.
RED wire carries the brake light input signal and connects to the cold side of the brake light switch (the side that carries a signal only when you press the pedal).
WHITE wire is ground and connects to the negative battery terminal.
BLUE wire is the controller's output signal that gets routed to the vehicle 7-way socket to activate the trailer brakes. On a typical 7-way this connects to the pin at the 5-o-clock position as you look at the back of the truck. Please refer to the linked photo.

On my install.

The BLACK wire from the prodigy is connected to the BLACK wire on the 4Runner
The RED wire from the prodigy is connected to two thin GREEN wires from the 4Runner.
The White wire from the prodigy is connected to the White wire from the 4Runner
The Blue wire from the prodigy is connected to the Yellow wire from the 4Runner


PS After UHaul I took my 4Runner to the dealer to figure out what was going on. Evidently, they turned out the headlights and when the problem went away they did not know what to do. Its no clear that they actually checked the brake wiring.

 

If you paid someone to install it I would take it back to them and tell them to fix my shit.

 

While I appreciate you coming to us to ask and attempt to troubleshoot this, I would 100% tell uhaul to fix my shit.

This is good not only to get the product you paid for, but to also cover your ass should you attempt to fix their mistake and they won't warranty their work because you messed with it.

 

UHAUL is anything but professional installers but I would also be taking it back there.

 

UHaul was a $45 bill. They were reinstalling a unit I brougth there for my own trailer not theirs. If they knew what they were doing they wouldn't have messed this up. Now, I have no condidence in them, and no patience that they would it right or that I couldn't figure this out myself with some help from my friends There are only four wires and I bet the black and white wires are correct. So that leaves two that may be switched. If anyone knows the answer I would sure appreciate advice.

The whole issue of auto work being done correctly is another matter. I have found that in too many instances "techicians" don't have enough pride in their work to get things right. Example, The numbnuts in the Toyota dealer jut put one of thier electronic guizmos and the read out told them that everthing was fine. I

 

I thought we had plug and play trailer brake controllers in these, under the driver side dash. My Tahoe came with the pig tale, but the trailer brake controller popped right in the spot for one. I was hoping the same for my 2022

 

Problem solved. I am leaving this message should someone esle have the the same question.

Turns out that there is a pigtail made for the Prodigy Brake Connector specifially to connect to Toyotas. Sells for $15 on Amazon. Fixed my problem and would have saved me time and money. I didn't fine the answer in this forum though.

If you are interested in why the orginal wiring didn't work, its the extra ground. Look at the wire harness. White goes to white in the plugs, but there is another ground that needs to go directly to the chassis.

Good luck!

 

So you have to connect the ground to the chassis inside the vehicle?

 

Yes, apparently connecting the wihte (ground) in the Prodigy to the whte wire in the Toyota connector is not enough. There is a seperate while ground that needs to be connected to the chassis. This is what Uhaul missed.

 

Interesting, I wonder why it wants 2 grounds. The one for my Tahoe was literally plug and play I didn’t even need the stock harness

 

And any picture of where you connected that ground by any chance that is easy to connect and disconnect?

 

I connected the ground to a 10mm nut near the acellerator pedal. It was clearly an all metal connection and easy access to the prodigy installed onthe right side of the lower dash.

When I tried a direct connection w/o the extra ground the ABD and the slip indicator idiot lights came on. No problem now.