Tacoma trailer hitch wiring issue

Hi guy. So i installed one of thos 4 position hitch wiring kits on my bone stock '04 Prerunner and have a problem. If i hit the breaks now while the left blinker is on it goes to a fast blink and my ABS light on the dash comes on. Disconnecting everything and restarting fixes all. I checked and all my bulbs appear to be in working order and i have a good clean paint free grounding point too. Install seemed fool proof. Any guesses? Thanks in advance!

 

How does the harness wiring attach to your stock wires? Can you run a continuity check with a multimeter to see if any of the wires are crossed in the harness?

 

If it's an aftermarket one.
Take it back and get another one. Sounds like the converter box is junk.
If you wired it up right that's the only cause.
Strongly suggest you go factory...
I see way to many issues like this.