Horn button swap

Last year I swapped the handlebar controls on my 1974 850 MK II so that the turn signal lever was moved to the left side of the handlebar. I had found it a little uncomfortable with the turn signal lever on the right where the throttle and front brake lever are located. The relocation also meant that pushing the turn signal lever up indicated a right turn and pushing it down indicated a left turn, similar to the way a turn signal stalk works in a car, at least here in North America. However, the swap put the horn button on the top of the right side switch cluster. I’d like to return the horn button back to the left switch cluster. I think this can be achieved by disconnecting the purple/black wire from the horn button from the connector block under the fuel tank and replacing it with the white/red that goes to the existingspare button on the left switch cluster. My question relates to the white/red wire. My wiring diagram shows the white/red wire leaving the handlebar switch cluster and going into one side of a connector under the tank with no wire coming out of the other end of the connector. However, on my bike there actually is a white/red wire that comes out of the connector and appears to be heading towards the rear of the bike. I haven’t been able yet to trace where the white/red wire goes after it leaves the connector. Does anyone know where this white/red wire, which according to the wiring diagram doesn’t exist, actually might go?

Spare button was for future electric leg starter I believe. So when I did this same swap on my 74 850, I think I just used that wire to activate horn and all is good.

BTW, I have my turn signal switch toggling up for left and down for right...which I associate with up/leftward swing og my left thumb to signal left and down/rightward swing of thumb to activate right lamps. Works well for me.

Tornado said:

Spare button was for future electric leg starter I believe. So when I did this same swap on my 74 850, I think I just used that wire to activate horn and all is good.

BTW, I have my turn signal switch toggling up for left and down for right...which I associate with up/leftward swing og my left thumb to signal left and down/rightward swing of thumb to activate right lamps. Works well for me.

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When you swapped the wires, and put the white/red into the connector where the purple/black had previously been, did you notice if there was another white/red wire coming out the other end of the connector?

WEM said:

Does anyone know where this white/red wire, which according to the wiring diagram doesn’t exist, actually might go?

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The white/red wire comes out of the wiring harness near the carburetors. It has a push on spade connector. Next to the white/red wire is another white/red wire with a spade connector and it goes back into the harness and then exits out of the harness near the battery area. None of these wires are hooked up to anything.

Peter Firkins

PeterJoe said:

The white/red wire comes out of the wiring harness near the carburetors. It has a push on spade connector. Next to the white/red wire is another white/red wire with a spade connector and it goes back into the harness and then exits out of the harness near the battery area. None of these wires are hooked up to anything.

Peter Firkins

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Perfect. Thanks. I was curious regarding why the wiring diagram didn’t show the white/red wire when it exists. Was concerned it might connect somewhere I couldn’t see.

WEM said:

When you swapped the wires, and put the white/red into the connector where the purple/black had previously been, did you notice if there was another white/red wire coming out the other end of the connector?

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Cannot recall, but if you mean the 5 block rubber multi under the tank, then I suspect not, as there would be nowhere to go with that red/white.

WEM said:

Perfect. Thanks. I was curious regarding why the wiring diagram didn’t show the white/red wire when it exists. Was concerned it might connect somewhere I couldn’t see.

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I believe the mk3 schematic does show this wire running to the starter solenoid which would live on the frame gusset near battery tray I believe. My Haynes manual has the MK3 schematic.

Tornado said:

Cannot recall, but if you mean the 5 block rubber multi under the tank, then I suspect not, as there would be nowhere to go with that red/white.

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It should continue through the harness to the battery area along with a white/purple, neither of which are on the wiring diagram presumably because they don't connect to anything.

Tornado said:

I believe the mk3 schematic does show this wire running to the starter solenoid which would live on the frame gusset near battery tray I believe.

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Yes, as those wires are used on the Mk3.