Switch schematic

[AgentX]

Hi everyone-

I have an Indian bike with the Swiss-brand LH control/decomp switch, like this one:  click here.  (Different from export models since you can turn off the headlamp.)

Trying to determine which wires are intended for which purpose so I can wire into a non-factory setup.  I've done the obvious...figured out power supply/output to the turn signals; green and one blue seem to be headlight output; purple goes to the horn button.  Am making a guess now that the red/white is power input for the lighting (it splits and connects to both the light on/off and dipper sides of the switch, so that seems to make sense...)

I will test to find out for sure, but figured it'd be easier if someone happened to have a schematic of the stock wiring.  There are yellow and yellow/red, 2 gray, and second solid blue whose functions aren't obvious and it's a little hard to see how the switches work without disassembling it all the way.

To function test the switches, can I attach the red lead to positive on a charged 12v battery, my multimeter negative to the battery negative, then look for voltage at the various wire ends in all the switch positions?  Or will I blow something out at the switch?  Could I use a household 9v or something instead of a vehicle battery?

Also, how does the horn ground??  I get continuity from the purple input wire to the inside of the horn button when I depress the button, and it cuts off when I release it.  Is the switch just grounded by being in contact with the handlebars?  That seems like a sketchy connection, especially since my bars are powdercoated.

Thanks!

-Mike

[AgentX]

OK, after lots of time with a split-open switch, multimeter, alligator leads, and a 9v battery, I have myself a picture of how I can make it work! 

Long story short, I came up with this chart:



Excited that I managed to take care of this question myself.

Still curious about the grounding of the horn, though.  I am going to wire it so power enters the horn then exits to the switch, where when pressed, it should ground and complete the circuit.  This is assuming the switch can just ground at the bar, which seems weird but the only possible way to wire it...there is only one lead in and no lead out from the horn button.  And it worked before, so soldering a lead on would seem to be unnecessary.




(And here's the long story long, for those who care to read about my experiment:

I made a chart showing how all the possible switch positions give power to the various wires.  I then hooked 9v battery positive power up to the wire I was testing as an input, and attached the negative lead from my multimeter to the 9v negative terminal.  Then, I could test for 9v output at each wire which came off the switch.  Put an "X" where I found voltage, and voila.  Well, not quite voila...after wondering why no single wire gave me a useful output, I realized it was because I'd need to use multiple wires.  The charts for red/white and yellow seemed to mesh well, so I gave them both power and came up with the chart.

Deduced the intended function of each wire based on which switch combo activates it, wrote it in on the chart, and I'm set!!)

[LarsBloodbeard]

To function test the switches, can I attach the red lead to positive on a charged 12v battery, my multimeter negative to the battery negative, then look for voltage at the various wire ends in all the switch positions?  Or will I blow something out at the switch?  Could I use a household 9v or something instead of a vehicle battery?

Also, how does the horn ground??  I get continuity from the purple input wire to the inside of the horn button when I depress the button, and it cuts off when I release it.  Is the switch just grounded by being in contact with the handlebars?  That seems like a sketchy connection, especially since my bars are powdercoated.

For future reference, you can use any voltage.  Just keep it below 12v as the switch will have a max rating.  However, you don't even need to do this.  Simply switch your multimeter to resistance mode and see when you close the circuit.  No voltage needed.

Regarding the horn.  Many cars/bikes have a common ground.  The negative terminal of the battery is usually wired directly to the frame and/or engine.  As you surmised, paint, dirt, etc. can cause issues with this type of setup.  Saves a lot of wiring though!  Poke around till you see where it should be contacting the bare frame and sand a clean spot there.  I've noticed most things on my RE have redundant ground wires.  I've actually removed them on the turn signals and brake light.

[LarsBloodbeard]

Oh and mine is also from India.    The guy who originally owned it lived in India and brought it to the states with him.  So I can turn off my headlight and running lights too!

At some point I want to simplify the wiring and install a classic control kit, with METAL controls instead of plastic.  Also I just want to redo it all because I have a little bit of electrical bleed somewhere in the system.  Battery voltage drops pretty quickly when it sits.

[AgentX]

For future reference, you can use any voltage.  Just keep it below 12v as the switch will have a max rating.  However, you don't even need to do this.  Simply switch your multimeter to resistance mode and see when you close the circuit.  No voltage needed.

Regarding the horn.  Many cars/bikes have a common ground.  The negative terminal of the battery is usually wired directly to the frame and/or engine.  As you surmised, paint, dirt, etc. can cause issues with this type of setup.  Saves a lot of wiring though!  Poke around till you see where it should be contacting the bare frame and sand a clean spot there.  I've noticed most things on my RE have redundant ground wires.  I've actually removed them on the turn signals and brake light.

Thanks for the meter tip--I am obviously working from a pretty basic understanding of stuff.  But using a 9v was definitely easier than dealing with the vehicle battery for sure.

The horn problem is that there simply is no ground wire coming off the switch for the horn...I would wire it in to my planned common if there was.  This is why I'm confused; it seems as though switch housing to bar contact is the only ground and that hardly seems reliable.  Had expected to find a wire, but there's just an input (violet) which gets continuity with the inner portion of the button housing when it's pressed.  And it's not missing a wire...it worked like this as the bike was set up before.  Unless I'm missing something big?

Best of luck with your own wiring work.  I'm not totally averse to plastic myself...at least it doesn't rust!

[barenekd]

The horn button does just ground to the handlebars. 
See if the attachment helps.
Bare

[LarsBloodbeard]

The horn problem is that there simply is no ground wire coming off the switch for the horn.

That is nominal.  Usually grounding is accomplished simply by chassis contact.  There will be a metal part in there that is making contact.  Probably by pressing against the bar when the two halves are clamped together.

[AgentX]

Cool--thanks for the help, guys.