A:Answer That is usually due to a grounding issue in your electrical system. How were you connecting the device? Straight to the battery or through your cigarette lighter? I would suggest having someone check you ground cable and your entire electrical system to be sure it is operating correctly, including your cigarette lighter. The wires on the cigarette lighter can often become loose, which may disconnect the ground. There is a small chance the unit was defective as well, although it is more likely a ground issue.
