headlight problem

well im new here with my first bike, its a 1982 yamaha xs400j, and when i got it theheadlight was messed up the guy PO told me there was a short in the killswith/start box, and if you jiggle the start button the lite would tun on, well thats what ive been doing, well now it aint working at all, and was wandering if anybody had any pointers, i checked the fuse it was fine, ive take the kill/start box apart and don see anything wrong, any help would be great

 

Have you tried to bypass it? At the very least you will understand where the problem is.

 

what exactly should i bypass, sorry that mite sound dumb, but im new to bikes

 

First thing I'd try is cleaning all the connectors and check all the wiring for breaks... oh yeah, if you've been reading, get that fusebox swapped out too.....

Thinking, the kill switch is on the opposite side of the light switches, so if you jiggle the wire and thing moving will be inside the "rats nest" mess of wires in the headlight bucket. You will need to brave it inside there, tidy it up. I wen in and cleaned up things . used twist ties to keep wire groupings together and fee up some room behind the light.... maybe he just has everything mashed together putting pressure on the connector to the bulb.

 

Agreed with Za, check inside your headlight housing for bad connectors or something that it shorting out. Almost sounds like a bad ground somewhere.

 

on these bike, where is the ground? is it a common ground for a few diff things?

 

1 on each side,
1 from the negative battery terminal
Other under the left side cover above the air box.
With the bolt that holds the plastic play with the Reg/rect unit and TCI box
Be sure they are tight, killed a reg/rect by having that one loose :/