Topic: tail light / brake

[Ernest]

I've just gutted the stock wiring harness and eliminated some wiring on my cb750k4.  I put new super bars on and got rid of the idiot lights by replacing with brackets from 78 cb750F and mounted the speedo center by getting rid of the tac.  I'm using a lower profile tailight and I have forgotten how the wiring hooks up.  Everything works good, headlight, blinkers, speedo light, but I'm feeling alittle embarrased that I don't understand the wiring for the tail light. 

Is it..brown is for running light and green/yellow for brake and what causes the light to go brighter when braking?  Does it get brighter when the brake switch is turned on simply by providing more juice? 

Does the green ground attach anywhere inside the tail light housing?...just to the housing itself?

If the green wasn't attached to the housing would this not allow the brighter light when the brake switch is on?

The new tail light has a black and red wire...what hooks to green/yellow and what to brown?

[TwoTired]

The brake/tail ight should have three connections.
Brown is the low wattage running light/filament.
Green/yellow is the higher wattage brakelight filament.
Green is the lamp socket common ground for both filaments.

Cheers,

[justinmcgiver]

I just got a new "Lucas Style" tail light and it also just has just a black wire and a red wire. I also noticed it has a 2 filiment bulb. Haven't gotten around to installing it yet but it looks like I'm going to have the same problem as ernest.

[Ernest]

turns out black is low watt (brown) and red high watt (green/yellow), the solid green just attaches to the lamp socket and I've got a brake light / running light.  Once I finally got that concept understood it's not all that difficult to come up with your own wiring harness and eliminate what you don't want.  I found this animated schematic and this simplified schematic at honda chopper to be the most help.  Thanks