I am also losing power to the gauge lights and don't know why.There is a harness to my headlight with a Grn/Yellow/Blk and a Dark Blue with Brn strip wires.I have the first three figured but what is the Dark Blue with Brn stripe?
Seems like a ground issue, clean up the grounds, (next to battery, both front turn signals, and on the engine, check the battery.
Does my headlight only light up when the bike is running?
For the most part, like the previous post stated, with out knowing your bike, I am going to say, (YES)
Note: top corner, it says "control panel" go down to where it says signature, and put your bike info in there, (like mine down below) you will find its an easy place, where you dont' have to tell every new thread what you have, and if you put extra info in there like mine, I don't have to dig far to remember what my oil filter number is, or something that is important.
Also in the mass of wiring behind the headlight there is a brown wire and a green wire with female bullet connectors.Are these the turn signal wires?
Only if it goes into a signal. There are Free manuals on this website, so first off the easy place to begin is the 2nd sticky, and click manuals. Then if you do a search for "Free re-run manuals" you will find this link, (by me)
http://www.xs400.com/forum/showthread.php?t=14495 (weird) Also if you search wire diagrams, you will find alot of them out there, a common one for the post 1980 bikes seems to be the same basic diagram, that I happen to post along time ago, (2010 i think) Oh yeah, that is under the Tech link on top of the screen, and it (is dated, there is newer stuff, just search for it) but at least that will get you going in the right direction, in fact I just remember Willem put up a thread, marked (a bunch of how-to's in a thread)
http://www.xs400.com/forum/showthread.php?t=10715
Good luck, I didn't see an introduction, if I missed it, welcome to the club!
Does my headlight only light up when the bike is running?
For the most part, like the previous post stated, with out knowing your bike, I am going to say, (YES)
There is a relay, that checks to see if the stator is moving, it is sensitive enough to take false positives, and turn on your headlight. Ohhh the threadssssss