Yamaha XT660R Service Manual page 451

TRBL
SHTG
FAULTY LIGHTING OR SIGNALING SYSTEM..............................................9-6
HEADLIGHT DOES NOT COME ON ........................................................9-6
HEADLIGHT BULB BURNT OUT.............................................................. 9-6
TAIL/BRAKE LIGHT DOES NOT COME ON ............................................9-6
TAIL/BRAKE LIGHT BULB BURNT OUT.................................................. 9-6
TURN SIGNAL DOES NOT COME ON .................................................... 9-6
TURN SIGNAL FLASHES SLOWLY .........................................................9-6
TURN SIGNAL REMAINS LIT...................................................................9-6
TURN SIGNAL FLASHES QUICKLY ........................................................9-6
HORN DOES NOT SOUND ...................................................................... 9-6