I'd go with RadioMarty's advice and check the position of the handlebar grip first .The handlebar grip on the Left Hand Side has a small raised area that is meant to house the microswitch , if the grip moves or rotates you can end up with a part of the grip constantly pressing the red button . To check , disconnect the battery first, then just press and release the switch a couple of times. You should hear a nice healthy click . You can also pull back the grip to reveal the microswitch and check to see if it is working correctly.