The conductance properties of 1,3-(trimethylsilyl)-1-tridecene-6,12-diyne, a non-conjugated trimethylsil-acetylene molecule have been investigated both experimentally and theoretically. Based on scanning tunnelling spectroscopy experiments, a discussion on the mechanisms controlling the charge transfer through this linear molecule is carried out. A specific property of the studied molecule is that it contains localized molecular orbitals. The shifts of the MOs energy levels caused by the applied voltage as well as a distant superexchange coupling between the respective localized MOs are shown to become determining in the formation of a nonlinear hole current through the molecule.