Contrary to everything I've read here :umm:

[226dark]

I put a new headlight in 2 nights ago and it lighted up just turning the key. All along I thought it would come on once I finally started which it didn't because burned out lamp.

Is it some wacky wiring somewhere that allows this on my 1978 2E? Everything SEEMS in place. Once running it will do what it should and stay on whether light switch on or off, so all good there.

Other question i have - I did some searching for possible other forum members who don't have Tach and Speedo lights working, as well as High Beam indicator light. Thought I'd search before I actually have a close look. Was hoping the gauge lights would come on when running . . . . like the headlight supposedly is said to do. And are the two issues (non-issue?) related? Doesn't seem that way.

Here is one thread of numerous on the Headlight-when-running topic http://www.xs400.com/forum/showthread.php?t=5712&highlight=tach+light

 

[jayel]

first check you have voltage on both sides of your fuses, sounds like the starter safety relay may not be working, supposed to keep lights off until engine starts, the alternator sends voltage to the relay by the yellow wire which connects the Red/Yellow to Blue/Black lighting headlight and guage lights, this wiring diagram is for the 79 but 78 is the same as far as how the relay operates
http://www.xs400.com/forum/showthread.php?p=75072#post75072

 

[226dark]

first check you have voltage on both sides of your fuses, sounds like the starter safety relay may not be working, supposed to keep lights off until engine starts, the alternator sends voltage to the relay by the yellow wire which connects the Red/Yellow to Blue/Black lighting headlight and guage lights, this wiring diagram is for the 79 but 78 is the same as far as how the relay operates
http://www.xs400.com/forum/showthread.php?p=75072#post75072

Thanks for the reply, looks to work the same as the main / "turn" relay (maybe not called that since it doesn't have a starter).
Turns out I happen to have two and both have the continuity and same ohms as. . shown in picture. The only continuity is between the yellow and ground terminals.



I'm a little perplexed though upon a closer look. I tried to take a pic that can be seen since wiring pics are usually hard to decipher what's the what and where it goes. The relay wire is SB/B - Sky blue and Black (black insulation near connector makes it impossible to see here). Continuity from relay to there. After not understanding something that was seemingly odd I took the headlight bowl off.

The Blue/B to right switch and then also another Blue from right switch which seems to have no place at all for the bullet connector. Turns out it was folded over and taped around, maybe by PO, not sure It would seem this is necessary and belongs somewhere. After some time spent still no instrument lights and the headlights are on when key is turned, all same. Any thoughts on this? Please? Thx guys!

 

[226dark]

I regret the title of the post, sounds condescending or something. Not what I meant and maybe 1978 to 1979 different, don't know

 

[226dark]

Thanks for the reply, looks to work the same as the main / "turn" relay (maybe not called that since it doesn't have a starter).

Went to bed not sleeping and realized I answered my own question. It doesn't have a starter!
I used a test light from batt. Neg. to Ignition switch L/B for instrument lights and good. Ground side good too. FIVE burned bulbs! one of which was broken, the one from high beam looks strange unless supposed to be that long bulb.
Not surprised.

As for headlight being on all the time, I am going to assume it's meant to be that way for 1978 2E and be happy with that. Can just leave the switch OFF and it will turn on when it is running.