an electronic control circuit for a vehicle cathodic protection system is disclosed . a battery of the vehicle is utilized to supply electrical energy to the circuit . the circuit includes a first voltage comparator which compares the voltage level of the vehicle battery with a predetermined reference level . if the voltage level of the vehicle battery falls below the reference level , the first voltage comparator disables the control circuit so as to prevent an undesirable drain on the vehicle battery form occurring . an oscillator provides a pulsating output signal . when the output pulses from the oscillator are positive , a transistor switch is turned on to cause electric current to flow to one or more sacrificial anodes . when the output pulses are negative , the transistor switch is turned off , thereby preventing electric current from flowing to the sacrificial anodes . thus , the control circuit is only energized intermittently . a pilot light is responsive to the positive output pulses from the oscillator to generate a visual indication when the control circuit is energized . a temperature regulator is provided to disable the control circuit , by means of a second voltage comparator , when the ambient temperature is too high .