The detector only gives you a green glow if you have the detector object. It does not allow you to move through objects or walls.
If you want to go through walls, you'll need to make sure layer 3 is not occupied. Right click layer 3 to toggle the visibility of it in the editor. If your path does not show up, then the player can't reach it. So move the walls from layer 3 to 2, 1 or 0 in order to fix your problem.