Hello Everyone,

I'm having a unique issue with an aftermarket left-side handlebar control. I still have the stock one for testing but the housing is smashed from the previous owner but the switches still work. I am running a 12v system just an fyi.

 - When using the aftermarket controls I have no headlight with a 12v power source, OR with the bike running, horn works, signals work, but gauge lights do not.
 - With the original controls the headlight works both with the 12v power source and with bike running, no horn (could just be a faulty button from age), but gauge lights work.

Are there different pin-outs on these aftermarket controls by chance? Some of the colors are most certainly different, but something not right. What's odd is that I can measure 12v at the plug with the aftermarket controls and the high/low switch verifies that but the headlight simply will not illuminate. Quite odd and I'm at a bit of a loss.

Stock Pin-Out
Aftermarket Pin-Out

Thank you,
~Steve

 from near Salisbury, UK.

As you guessed, makes no difference if 6v or 12v.

Quite possible that your new switchgear is for a different market bike than your original.

Is the inside of the housing on the new switch identical to your old one? If yes, you might be able to fit the old internals into the new housing. If no, I'd be tempted to look for another original switchgear - consider a cheap one with an intact case but butchered wires, so that you can just swap over your existing internals. When searching, also use the YHA number on the underside of the original housing, as these often turn up cheap as "unidentified".

Ummm... those are pictures of wire connectors you've called "pinout". Pinout would usually tell you what color wire does what.

Yamaha wiring diagram should have legends that tells you what wires connect to what wires in the different switch positions.

SOMETIMES the seller of an aftermarket switch has a legend that tells you what color is what... then you might be able to match the wires and rearrange them in the connector to match your original Yamaha connector.

Also, it's important to have the exact same functions in the switch... A 74 should have the headlight "on-off" in the handlebar switch... earlier model switches don't.

If you don't have a wire color legend for the new switch, all is not lost. With a continuity tester and a little bit of time you can map out the wire functions on the new switch. Carefully looking inside of your new switch to see where each color wires go and looking inside the Yamaha switch to do the same can be a huge time saver... I would verify with a continuity tester (ohmmeter, powered test light, etc) to be certain.

When done you should have a list of Yamaha wire colors that correspond to the wire colors in the new switch. Then you just need to make sure the wires are arranged in the connector in the same way.

Okay, I looked at the Yamaha Service Manual and didn't see a "switch legend" like some of them have.  So I'll try to make one for the Yamaha switch in the order I would try to map them for your new switch.  There are several individual switches inside the handlebar switch

DT360 handlebar switches and wire colors

Horn 1 wire
Pink -  Looking inside both switches, you should hopefully be able to see which wire color on new switch goes to horn button.  It's pink on Yamaha switch

Turn Signals 3 wires
Brown/White - Comes from turn signal flasher - powers center terminal of three wire turn signal switch inside handlebar switch.  What color wire goes to center of turn signal switch in new switch?
Dark Green- Powers right turn signal, connected to brown/white when switch is in "right" position.  What color is this on new switch?
Dark Brown- Powers left turn signal, connected to brown/white when switch is in "left" position.  What color is this on new switch?

Headlight on-off (and high-low)
Yellow/White - in from stator
Blue - Connects to Yellow/White when headlight switch is on
Yellow - Connects to blue when headlight high-low switch is in "high" position
Green- Connects to blue when headlight high-low switch is in "low" position

Of the above, the two interconnected headlight switches are maybe the trickiest?  If you take a look inside the switch it's not so hard. Yellow and green will be outside wires on high-low switch with center terminal on high-low connected to a jumper wire that connects to blue on output wire of headlight on-off switch. 

But again, if new switch doesn't have the same functions as old switch, it won't work.  But if they are the same, you should be able to map the new switch and move the wires around in the new switch plug to match the Yamaha wiring.

P.S.  Yamaha high-low switch has a feature where as you move the switch, both high and low are connected until you get to the new position.  This is because if there was a "dead spot" between high and low the voltage would spike and you probably would blow the headlight beam when the connection was made.  So for example if switch is in low beam position, as you move it toward high beam there would be a moment where both high and low are connected until you are on high beam...there's no place when sliding switch that one or both beams are not connected.  Thanks to DEET for pointing this out.  I've found the couple of aftermarket switches I've used behave the same way...  but if you find your headlight blowing when switching beams, now you know what it could be.
 

Darn. Forgot that headlight on-off switch will also have a different blue that connects to brown when on.

So one of the blues will likely be blue/white.

Really hard to do this from memory without having the switches in front of me.