in my code the turtles won't move when the patience is smaller than friction

Question

to go
  ask turtles [
  if patience > friction [ speed-up
    set color red
     fd 1
    set walk-score walk-score + 3
    ]
    if patience < friction [ speed-down]
    ]
  tick
end
to speed-up
  set speed speed + acceleration
  if speed > speed-max [ set speed speed-max]
  fd speed
end
to speed-down
  set speed speed  - deceleration
  if speed < speed-min [set speed speed-min]
end

Answer 1

Now you didn't give much context, but wouldn't you need to call fd speed in speed-down to to move the turtle? Just based on intuition that looks like the code that actually moves the little reptile.