Turn signals turn on when I hit the break.

I would take the dash apart again and looked for pinched/shorted wires. Also, the electric brake controler connects into the wiring system to activate the lights doesn't it?

 

Disconnect your brake controller 1 wire at a time. You might have the ground wire hooked up wrong. Power goes to brake light feeds back thru turn signal

 

Um No. The trailer brakes work with electro magnets in the drums. The more voltage to the the trailer the more the brakes apply.
Yesteryear the blue wire in the center of the trailer cord was for accessories. We used them for backup lights on trailers that delivered auto parts all hours of the night. Connected to a toggle switch.
Also connected them to battery banks which ran lift gates or ramps. Put a 15 amp breaker inline that would open when the motor ran. It would reset and charge the batteries.
Now you are out of wires and that is for ABS. If you tied into that your truck likely has a headache.
I have never done this but would probably try this. Connect the BLK and BRN wires on the trailer plug together on the BRN terminal. Then connect your brake control wire from the controller to the black terminal on the 7 way tractor plug. No other wires from the truck with it.
Connect your trailer brake control wire, from the wheel magnets, to the black terminal on the trailer connector.
If that is the only trailer you pull you could go old school to the center. However it you pull different trailers your ABS will be disabled. What I outlined could be considered overloading circuits but LED lights do not pull much.

 

Best the put a different plug at the back of the truck for electric brake trailers. How did you do that?

 

Where did you splice the brake light wire (blue) into in the truck? You should splice it in at the brake switch and not the rear trailer plug.

 

It has to go to the rear truck lights, not the trailer circuit, they are wired different, two light system on the truck and 4 light system on the trailer.

 

What was it?