We synthesized 4,5-bis(octadecylthio)-4',5'-bis(ethylcarbamoyl)tetrathiafulvalene and measured the electrical conductivity of its perchlorate-doped nanofibers, which have double and triple helix structures. Temperature-dependent conductance and current-voltage (I-V) characteristics of the coiled fibers were measured in the temperature (T) range of 70-300 K. The results were analyzed by using a modified fluctuation-induced tunneling conduction model.