[Raystar57]

This seems like the throttle control signal is reversed and you are at full signal to start.
I don't know if this controller has a programmable function for that.
Maybe you could try to swap the L and G terminals in the cable.
This would reverse the throttle input signal.

Oh, I see you say it make no difference in speed, like slow down the more you push.

Maybe the throttle control pot is bad somehow.

Can you test it with an ohm meter to see if it does vary resistance through its travel.

I am not sure of your throttle control unit. I am a Club Car guy.