Topic: Wiring Harness

[katman]

Okay, Since a short somewhere in the other harness that kept blowing my 15 amp fuse everytime you turn the key on was not found, I got another harness. But the plug for the ignition switch does not have the brown jumper wire like the other. See pic.
Other than that the harness is the same, What is the jumper wire for and should I be concerned. Pic has old plug with jumper
beside new one.

[jheck10]

What year and model?

[katman]

1977 750 K

[Don R]

It appears in the top one the brown is fed from somewhere upstream, in the lower one the brown gets it's feed from the black wire at the plug.

[goldarrow]

My 750k6 came with a jumper wire like that.  I thought it was a total hack job, so I trashed the jumper wire and went to town sorting out the electrical.  It was fun. 

[katman]

It's brown, red and black across the top. On the bottom it's brown on one side and the jumper brown from the top on the other.
Bottom middle slot is open

[katman]

Okay, After studying wire diagrams the 78K and 77-78 f models show this jumper wire on the switch. Mine is a 77K, but looking at the switch diagram
I can't tell what it actually does. Any wiring guru's out there. I would like to know it I can use this harness before I put it back on.
Thanks Again

[iron_worker]

Mine (K4) requires a jumper from brown to black inside the headlight bucket so I'm guessing this was just a factory method of accomplishing the same thing. I believe there are some small differences like this on the various harnesses as they were available for Europe, North America, etc since they had different lighting laws.

IW

[katman]

Yes, I see that jumper inside the headlight bucket. This is the plug that goes into the bottom of ignition switch.

[iron_worker]

Does the harness that has the jumper in the bucket also have the jumper on the ignition switch?

IW

[goldarrow]

Jumper in the headlight bucket is probably and most likely needed, but I don't think your ignition key needs or should have one....

[katman]

I think I'll install the harness and see what happens

[74750k4]

Okay, After studying wire diagrams the 78K and 77-78 f models show this jumper wire on the switch. Mine is a 77K, but looking at the switch diagram
I can't tell what it actually does. Any wiring guru's out there. I would like to know it I can use this harness before I put it back on.
Thanks Again

Those wires supply almost everything using 12 volts on the bike. It appears it simply doubles the current capacity of the connector, since it would be using two sets of contacts, instead of one set. That way the current is shared, and the capacity doubled, through that connector, reducing the chance of burning/overheating at the connector. The brown color doesn't make much sense. Those are hot wires.