Characterization of the different precipitates developed in supersaturated Al–1.12Mg2Si–0.35Si (mass%) alloy by thermoelectric power (TEP) and electrical resistivity (ER) measurements was considered. The effect of precipitation of coherent, semi-coherent and noncoherent phases on the TEP was found impressive in describing different precipitates. Upon growing and coherency loss of b0 particles, the TEP increases to reach a maximum value. TEP begins to approach a stable value by the formation of the equilibrium b (Mg2Si) precipitates and then stabilizes with the complete growth of more stable precipitates b phase and Si particles. The first-order coefficient a of the ER–temperature dependence was found dominating in the temperature range 300–635 K. Above this temperature range, the second-order coefficient b starts sharing effectively the resistivity–temperature dependence. Furthermore, it has been shown that the range of temperature in which the first-order coefficient a is dominating slightly increases after slow cooling twice to the room temperature in two successive runs. Correlation of a and b with the lattice rigidity of the alloy under investigation was established. Quenching and slow cooling affect strongly the observed correlation. All measurements in the present investigation were taken under non-isothermal conditions.