Garmin Cadence Sensor I have just changed the battery in my garmin cadence sensor on my road bike, but when I press the reset button only the red light shows but no green light. Anyone know why? Thanks
The red light flashes when the magnet passes the pick up sensor that you attach to the frame.  The same sensor has an adjustable "arm" on it to pick up the magnet mounted on a spoke.  It should flash green if it senses the magnet as it goes past the sensor arm.  My experience is either the arm and or the entire sensor needs to be adjusted.
Good luck.