Author Topic: Spare ground wire at the horn.  (Read 1881 times)

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Offline clintcd

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Spare ground wire at the horn.
« on: July 01, 2012, 11:31:48 AM »
On my 1977 cb750A there is an unconnected Green wire with a push on spade connector with the horn wires, a third wire is shuwn to the horn in the wiring diagram, also unconnented. Can anyone tell me why this wire is there and should it be connected.

Many thanks.

Offline salukispeed

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Re: Spare ground wire at the horn.
« Reply #1 on: July 02, 2012, 09:42:59 AM »
My 77 has the same wire and was never connected as far as I can tell. No idea why??
1974 CB750 K4
1970 CT70
1966 CA77 (305 Dream)
1984 GL1200 Interstate
1977 750A
1972 CL100

Offline raymond10078

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Re: Spare ground wire at the horn.
« Reply #2 on: July 02, 2012, 04:14:19 PM »
I only have a hunch.  In looking at the wiring diagrams for other countries (France), the horn was grounded - and the horn switch switched a positive source.  On our bikes, the horn is not grounded.  With the three wires - either type or horn/system could be used - just change some wiring on the assembly line - but the loom works for both.  So . . . maybe it was a "one loom fits all countries approach"?
« Last Edit: July 03, 2012, 11:40:51 AM by kandrtech »
1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.

Offline BobbyR

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Re: Spare ground wire at the horn.
« Reply #3 on: July 02, 2012, 04:36:31 PM »
This is the infamous green wire which appears in questions here regularly. It was never connected to anything. It is believed that the same harness was used on other bikes, maybe other brands. 
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline clintcd

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Re: Spare ground wire at the horn.
« Reply #4 on: July 03, 2012, 10:22:35 AM »
 ;)Thank you all for taking the time and trouble to reply, I will no longer wonder about this dangling wire.


Offline stinkfinger

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Re: Spare ground wire at the horn.
« Reply #5 on: July 07, 2012, 04:51:25 PM »
I have heard of  some electronics(outside of the US)
having an extra wire coming off the stator
as having a "floating ground".
No idea if it applies to this situation.

Tony
Dualsports are an all access
back-stage pass to nature.