how to use Y cables

i have tryed these on the motor inputs, trying to control 2 motors with the same button, but it has not worked. am i using them wrong?

“not worked” is a bad description.
Get a setup where one button controls one motor.
unplug the motor and put the Y cable in the middle, Does it still work?
add a second motor to the spare end of the Y, DOes that work the same?

Otherwise, try this format for a question:

  1. Here is my setup, and what buttons I pressed on controller.
  2. This is what I expected to happen.
  3. This is what actually happened, (not “doesn’t work”)

make sure the black cord is facing outside, and make sure they are plugged in colors- matching