Stoopid headlight or me?

[Sparki]

- 79 XS650 Special
- All original from my limited experience

Step 1: Speedometer needle fell off and faceplate began spinning...must needa new one.

Step 2: Got onto MikesXS.com and decided to do maintenance while I was replacing the speedo, ordered new fuse box, shocks, brake pads and speedometer. Decided to go with a mini-speedo that had some of the current tach lights incorporated into it.

Step 3: Shocks went in fine, brakes were easier, fuse box was plug and play mostly. Took off the headlight and felt like I'd cracked open someone's skull preparing for brain surgery.

Step 4: Removed speedo, tach, headlamp and those 3 lights in the middle. Found the "N" light and wired that into new speedo, found...at least the right turn signal indicator and have that wired in so it works although, it doesn't work for the left one without having emergency flashers, nice but not useful when cornering. Plugged the headlamp back in since there was no need to have it unplugged and found out the headlight wasn't coming on.

Here's the question: I don't have power coming into the yellow wire, as a matter of fact the last place I can reliably get power is on the exit side of the fuse box connector. So I cut a length of wire and jumped from the exit side of the fuse box straight to the yellow connector at the headlamp and upon just touching it to the connector the light came on. The light works fine, high/low beam, L/R signals work fine. I shut the key off and turn it back on and it goes back to not working until I touch it with the jumper again. Any idea on what's going on with this thing? I've been using the Hayne's manual diagram that most closely (in my unedumecated opinion) resembles the set up I have but either can't read it or don't see where this would be creating a problem. Thanks for the input ahead of time

 

[Blowtorch]

It sounds like it might be that gray box I think its a 12volt back up. Or something like that. I removed mine and things worked much better.

 

[Sparki]

The Reserve Lighting Unit? I jumpered the two blue wires and used a voltmeter earlier, sorry I should have mentioned it, and still didn't have any power to the yellow wires. As I understand it, what that does is kick in the high beam at a lower voltage in the instance that your low beam goes out. If I'm tracing the wires right on the schematic it doesn't go directly there though anyway does it? Past that once I removed the jumper from the exit side of the fuse box the light would go back out instead of staying on until the key was turned off wouldn't it?

 

[Q Tip]

Is your motor running? On the 79 the safety relay will not let the headlight burn unless it "sees" a charge coming from the alternator. This is to give more cranking amps to the starter. Other than that do you have power feeding into the left handlebar switch?

 

[Sparki]

Is your motor running? On the 79 the safety relay will not let the headlight burn unless it "sees" a charge coming from the alternator. This is to give more cranking amps to the starter. Other than that do you have power feeding into the left handlebar switch?

Nope, sure isn't. It's going to be a few days before I can let you know if it works, pulled the sump out, as badly as the screen was ripped I'd say it hadn't been replaced, so waiting on that one to get in. Thanks much

 

[Q Tip]

I'm in the midst of a '79 re-wire myself so as they say around here," don't feel like the lone ranger".

Look under the post," some wiring diagrams" in the tech section at the top of this page for a simplified diagram for the 1979.