Like Jathawk500 said, the issue is the insulated(isolated)rail is not isolated for some reason. A simple test is to have the power off and test continuity (ohms symbol - infinity) with the meter , of the isolated rail to any other rail. There should be none - 0 - no movement of the needle.
Check each side of the cut in the rail to ensure the cut is wide enough - then check that all bars are removed on the trigger track area -