Good morning. The left and right mechanism of the circuit you see in the photo is broken. How can I do this in a simple way? Does it make sense to connect a motor? The place shown in blue is the connection of the right and left channel.
I took out the cable and connected it to the motor ends and I couldn't get any efficiency.

 

I have 50 years experience of designing and building R/C electronics and actuators.
There is not enough information there for me to even make a wild guess.
I have no idea what the turn mechanism is or how it is supposed to work. I don't know whether it is proportional or simple left/center/right. I do not know what electronics are driving the mechanism.
The place shown in blue is one end of a very small, out of focus circuit board. What cable did you connect to which motor? There is not a motor visible in your photograph.