Headlight/Tail Light Failure Indicators

[cmyoch]

I got into the headlight bucket a week or so ago to trace a blinker issue and noticed a blue wire that's disconnected. It appears to be to the tail light failure indicator from a few of the diagrams on this forum. I rode today and noticed my headlight failure indicator was lit. I pulled over and reached out to see if I had light, I did. It was my tail light that was out (the running filament, not the brake filament). Part of me wants to leave well enough alone but another part of me is obsessing with making sure everything works correctly. I noticed on an evening run a while back that as my charging system would engage, the tail light failure indicator would very dimly light up. There must be some wires crossed somewhere.

 

[Skip]

On my 78, my headlight failure bulb would light up on acceleration.
Turned out the headlight was culperet,even though it was lit on both hi and lo beam.
Replaced it,light out!

 

[cmyoch]

That's what's happening with my tail light failure bulb though it's faint. That's why I'm only noticing it at night. It appears though that it isn't even hooked up which is what is perplexing. That is though unless that blue wire runs somewhere else? I'm pretty sure though that it's for the tail light. I had 2 tail bulbs blow now and both times the headlight failure bulb lit up.

 

[Skip]

Gotta believe something is crossed up.
I just noticed your signature
I have a 78 Special
I have a 67 Red Head Wife!

 

[cmyoch]

LOL! You're my Canadian brother!

I'll start doing some research on the wiring to see if I can get it straightened out.

 

[jayel]

tail light failure wires on a 78 SE are brown (power) and red/brown, head light failure is separate from brake fail, light green and black (ground)

 

[cmyoch]

Hmmm. Looks like I'll be tracing wires in the bucket again. I wonder what the solid blue wire is then?

 

[650Skull]

the 78/79Specials have the brake fail light doubling as a alternator charging light. If the alternator fails the light comes on and it would come on when the key is turned as well till it is charging right.

there is no reference to this from Yamaha or in the manuals

 

[jayel]

Hmmm. Looks like I'll be tracing wires in the bucket again. I wonder what the solid blue wire is then?

meter lights

 

[cmyoch]

That's odd, both have functional lights. I'll have to take a look again.

 

[cmyoch]

So over the past week or so, I've managed to replace my entire charging system with a good quality used stator and rotor, VR115 regulator, radio shack rectifier, blade fuses all around, and a new head light. The bike is running fantastic and charging like it's supposed to. Now my failure indicator bulbs do not light up when I hit the key and my head light does not automatically come on when the bike starts. I also disconnected my tail light yesterday to test the failure indicator and nothing happened. I'm assuming my safety mechanism has failed. All else seems to be functional and the bike is running great. Is there any reason to worry about this?

 

[5twins]

I would say no. I have that lighting safety relay disconnected on my '78 so the handlebar switch functions all the time, had it this way for several years now. Check the blue/black wire that plugs into the relay. That's the one running to the headlight. Unplug it and the handlebar switch works all the time, light doesn't come on with motor start any more.

 

[cmyoch]

That's good to know. I'm tired of the electrical system right now. I figured as long as it's running good, charging, and my lights are functional, I can deal with manually turning on my light.

I may knock off early from work today and enjoy a long awaited afternoon ride!

 

[retiredgentleman]

It appears that the Safety Relay is not working. When you did all of the electrical work, have you forgotten to re-connect the yellow wire that comes up from the alternator?

The SR has 5 wires. One of them is blue/black. It should have no voltage with engine off and "Lights" sw off. Start the engine. let it idle................blue/black should now have 13 volts (leave "Lights" sw off).

 

[cmyoch]

The yellow wire is connected. I'll run a test on the blue/black wire later this evening.