'78 Standard tail light question

[nhsteve]

Currently working on a '78 standard that even with 32,000 miles on it seems like it has had some real love over the years and miles. Lots of evidence of being well cared for. I bought it as a "runner - with a bit of help needed". I did hear it run on 2 cylinders, even rode it lightly (no front brake- caliper bleed screw completely buggered beyond repair). Things seemed ok beyond needing brake work and tires.

Soooo................ I've sorted the front brake, & replaced the cup/cone steering bearings (which had actually been repacked at least once, as the grease was quite good) with taper rollers. In the process of reassembling everything and checking light operation, when I turn the key on, the tail light comes on, regardless of the headlight on/off switch on the right handlebar switch (which does indeed control the headlight). Virtually all other lights act correctly/as one might expect.

Is this correct?

My '77 Standard does not do this, but looking at the schematics in my 'lovely' wink2 Haynes manual, I see that this makes sense (?). The '78 main switch has but 3 wires, red, brown, and blue. Key 'on' connects all three together, the blue lead goes right back to the tail light, I do not measure any odd voltage at the tail light, it just seems odd that Yamaha did this . If they put an on/off switch for the headlight, why have the tail light on all the time?

Any comments from another '78 Standard owner? I'm not going to obsess over it, just curious.

 

[gggGary]

78 was a transition year, 79 lost the headlight switch completely, taillight on all the time IS normal.

 

[5twins]

Yes, I have a '78 Standard and that's just the way it is - tail light on all the time (powered by key). Yes, kinda silly. I may change mine over by installing a '77 ignition switch. In the mean time, I've switched to an L.E.D. tail light bulb so the draw is very light. However, that triggered my "Brake" light warning light in the instrument pod. It was on all the time. I guess the light checker thought the bulb was burned out because the voltage draw was so low. I "fixed" that initially by simply taking the bulb out of the dash light, lol. Eventually, when I had the rear wheel off and could gain access to it, I removed the light checker (it's behind the battery box between it and the inner fender).

Something else you'll discover on your '78 is that even though it has a headlight on-off switch, it will only function with the key on, motor not running. As soon as you start the bike, the headlight safety relay will kick in and bypass the handlebar on-off switch. The headlight will come on no matter what position the handlebar switch is in. Another rather silly feature, in my opinion, but one that is easily remedied. At the safety relay under the right side cover, simply unplug the blue/black wire. The headlight won't come on automatically anymore and the handlebar switch will function all the time now .....

This "fix" can only be done on the '78 models as they are the only year set up this way.

 

[XSLeo]

The Key switch has a third position. This just powers the tail light. This was so if you had to park next to the road at night you could put the key in the "park" position. This lit the tail light. This was supposed to help prevent someone from not seeing the bike and hitting it.
Leo

 

[gggGary]

.... if you had to park next to the road at night you could put the key in the "park" "Steal me" position. ...
Leo

 

[XSLeo]

Yes, That can happen. If your broke down and trying to fix it. Not getting hit sure is a good thing.
Leo

 

[nhsteve]

Thanks 5twins for the reply and good explanation, and picture as well. I haven't tried to start the bike up yet, been busy with the family camp (i.e.- "life"). Back for a bit now so hope to get going on it again.
That third switch position seemed to be a "feature" back then (maybe even now???). I always assumed it was a DOT-required item.

Thanks again!

 

[nhsteve]

So, reporting back after I got the bike started and running. 5twins exactly right about the headlight coming on once bike is started. I may or may not fiddle the lead allowing me control over the headlight being on or not.

Another question then: the small meter light stays on all the time in the 'binacle', suggesting that there is a problem with the filament, but it is a new bulb, and I get both high and low beams just fine. Is this due to the light checker messing up? Thinking about just removing the indicator lamp.

Oh, and I just LOVE how an indicator tells me that the brake light comes on when I pull the lever . Yeah, that actually was my right hand that squeezed the front brake

 

[5twins]

Are you talking about the white idiot light at the top labeled "Head" ? .....

That's not controlled by the light checker but rather by the reserve lighting unit. Your RLU may be acting up, going bad, which does happen. Best thing you can do with that contraption is remove it, but it needs a couple wires jumpered to restore headlight function. Details are here .....

http://www.excess650.co.uk/tips & tricks.htm

The light checker monitors your tail light only. On a '78 Standard you should have the simple 3 wire unit. If so then yes, you can simply remove it without having to jumper any wires. That is what is illuminating the "Stop Lamp" idiot light every time you apply the brakes. The light will also come on if the tail light bulb burns out.

 

[fredintoon]

The Key switch has a third position. This just powers the tail light. This was so if you had to park next to the road at night you could put the key in the "park" position. This lit the tail light. This was supposed to help prevent someone from not seeing the bike and hitting it.
Leo

Hi Leo,
the "rear light only" switch position is for jurisdictions which require a lit rear light when parked after dark.
In North America that switch position's main use is to run your battery flat overnight when you accidentally
turn the key the extra click past locked. (First & last time I ever switched beyond ON and OFF)