In an earlier study we showed that C10 and C12 alkanethiol self-assembled monolayers on Au surfaces conduct only with significant applied stress and that the friction increases along with the increasing current, indicating significant changes in both structural and electronic properties of the film. In this presentation we outline results from a similar interfacial force microscope (IFM) study of hexadecane films near a Au(111) surface immersed in liquid. At room temperature, hexadecane forms mechanically stable surface multi-layers, which also inhibit conduction. However, under an applied electric field, the film structure is perturbed causing friction forces at extended separations but with no significant repulsion. We discuss these findings in terms of both the molecular and dielectric properties of the films as well as the effect of liquid temperature. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin company, for the DOE under Contract DE-AC04-94AL85000.