A turn signal reminder circuit for warning a vehicle driver that the vehicle turn signals may have been inadvertently left actuated. Turn signal flasher pulses are low pass filtered to provide a continuous enabling signal which initiates the operation of an astable, multivibrator timer circuit. The timer circuit switches asymmetrically between a first occurring longer-time, partial cycle and a shorter-timer, partial cycle. A sound alarm is enabled by the timer during each shorter-time, partial cycle. The alarm is actuated by flasher pulses when the alarm is enabled, but is disabled and the timer circuit is reset in response to operation of the vehicle brake. A pulse detecting circuit for using flasher pulses to turn on the timing circuit has no large capacitor and this permits miniaturization.