Marlin X_HOME_DIR 1 not working

Hi, I am trying to configure the endstops of my printer (Ramps 1.3 and Merlin V1) and they are all working if I put the endstops in the (-) axis direction and use _HOME_DIR -1.
However, I need to put the endstop of X axis in the positive end direction of the X axis. I suppose that I have t set X_HOME_DIR 1 in order to Marlin run in the positive direction of X to find the endstop when I hit XHome in Printerface. But it doesnt work. No action in Printerface when I hit Xhome.
Would please someone can help me to figure it out what is happening?
Thank in advance.

Is the endstop connected to the MAX endstop connection on the RAMPS board? If you don't move it from the MIN connection it won't work.

I didnt realize that the second, fourth and sixth position on the endstop conector was for the max endstops. I change the X endstop to the second psition and it works fine. Thank a lot.