A large part of the heat generated in the engine is removed from it by a cooling system consisted of coolant fluid and a radiator. In this paper, the use of Thermoelectric Generators (TEGs) and utilization of the difference between "engine coolant fluid temperature" and "ambient temperature" to generate electrical current, are studied. According to the observed results, from the engine start moment to about 10 minutes later, the TEG does not produce an electric current due to the low temperature of the coolant fluid. After a few minutes, when the engine's working condition and the temperature of the coolant fluid become stable, the electric current generated by the TEG becomes fixed, too. In this study, the air flow was applied in both forced and natural ways on the cold surface of TEG. Due to the continuous on/off of the radiator cooling fan, the temperature of coolant fluid comes out of the engine had a fluctuation about 7°C, which consequently caused continuous changes in the electrical energy level produced by the TEG. In the case of natural air displacement and forced air displacement on the surface of TEG, the average output voltage of the TEG in a stable state was about 357mV and 890mV, respectively.