Abstract: A malfunction detector circuit for use in conjunction with a pump-off control circuit which is periodically actuated by a timer and which monitors the current drawn by the drive motor of a liquid well pump. The malfunction circuit monitors the operation of the timer, pump-off control circuit, and drive motor of the well pump for detecting any abnormalities in operation and provides a signal if a malfunction occurs. The malfunction circuit is actuated by the pump-off circuit timer unless the pump-off circuit gains control of the driver motor and interlocks the malfunction output. A counter is provided to count a predetermined number of sequential failures before a malfunction is indicated. In addition, an excessive current measuring circuit detects malfunctions such as parted rods, split tubings, stuck valves and other abnormal situations.