the lights on my 450 only work when its in neutrel and the clutch is pulled in

sounds like you got something pluged in wrong. check the plugs under the fron and make sure the color on the wires match on both sides of the plugs

or maybe your bulb might have burned out but thats highly unlikely , check the wireing for sure

goog call

if the rectifier goes out it will burn both bulbs out, could be that problem. pull one of the lights out and check it with a volt meeter and see if you got power up there