Abstract: A position sensor for sensing the position of a moving part capable of actuating a plunger belonging to the sensor and more specifically a mechanism for orienting the plunger of the sensor. The sensor includes a guide that is rotationally orientable in a body about a first axis XX′ of rotation, and a plunger sliding without rotation in the guide along the axis XX′. A locator prevents rotation of the guide in the body about the axis of rotation, in a given angular position. The locator is fixed nonremovably in the body and possesses either several tabs spaced regularly about the guide and capable of fitting into one position groove to immobilize the guide or several position grooves in which one tab can fit to immobilize the guide. Such a position sensor may find particular application in detecting the positions of moving mechanical components.