Yellow wire/ Acc to the ignition/ switched power source.
The out put also has three pins as below,
Red pin + Black pin = Out put 5.3V, that is to power up the camera system.
Yellow pin + Black pin = Out put 5.0V, that is the signal to trigger the camera system starting or stopping work.
The converter can detect the Voltage of battery, more than 12V or less, and that generates two different performance.
When Motorcycle battery is more than 12V,
First turn on ignition,
Red pin and Yellow pin output 5.3V and 5V to power up the camera system 10 seconds later.
Then turn ignition off,
Yellow pin output will be 0V after 5 seconds, the camera system stop recording and save the last video clips.
Red pin output still has 5.3V output, but the camera system stop recording after 5 seconds and stand by.
Turn ignition on again,
Same as the first run.
When Motorcycle battery is less than 12V.
the difference compared to the battery is more than 12V is after turn ignition off, Yellow pin output will be 0V after 5 seconds, and Red pin out put will be 0V after 10 seconds. that is to protect the motorcycle battery does not drain.