Topic: Wiring harness Interchange

[Humble Pie]

Picked up a ratty 1975 that has a burned up harness ( in the battery area ) I have got it to where it will start kick and electric.  due to the damage I doubt the rest is good and well,,just needs to go.  I have a perfect 71 harness, would like to know if the color coding is the same and if the 71 will interchange ? Only immediate issue I see is the 75 has all its control wires inside the handlebars,,other than that what should I look for ?

Also is the a color coded map ( schematic )   for these harnesses for pluggin it all together ?

[HondaMan]

The '71 has a single fuse instead of 3, which goes in the RED wire between the battery and keyswitch. The '71 (and all "K" models before 1976) have the wiring inside the handlebars, so that's not different.

Overall, the '71 wiring is MUCH simpler than the K3 and later bikes. If yours has the keyswitch up under the gas tank, you might need to change the keyswitch connector (the '71 has a round plug instead of rectangular), and you can ditch the "safety module" altogether, along with the Clutch Switch. The wires on the Start Solenoid might be a different color, but the gender of the plugs should match up OK, no problem there.

If your bike has the keyswitch up in the instruments, then it's a little more complex, as the connectors don't match up unless you make a set of 4 jumpers from the like-colored wires (i.e., Black, Red, Brn, Brn/Wht) in the keyswitch connector to those in the harness round plug. But, if you plug these colors together, it will work fine.

[HondaMan]

Thanks,, my 71 had the wires on the outside not inside the bars ,,but no biggy thereI guess best to start from the front and just unplug and plug in the new ?

Yep. The wire colors did not change much, except you may find a light-Green/Red stripe wire in the harness (not the dark-Green/Red) that is part of the Safety Module circuit. You can just pretend it is part of the Start Solenoid circuit if yo need the wire, and connect it to the Yellow-Red in the right handlebar control. The Start solenoid's other wire then goes to Black, even if it is Green/Red. This comment all depends on which Start solenoid your bike has: some have a Yellow/Red and a Black, some have a Yellow/Red and a Light-Green/Red, and some have a Black and a Light-Green/Red.

[HondaMan]

I have some (3) that hold one ATC (automotive blade type) fuse, and it has a waterproof cap. They are 25 amp capacity, which is great for these 1-fuse bikes. One is headed for my own 750 shortly. If you're interested, I could send you one for $15, postage, connectors, and 15 amp fuse included. It doesn't have a "hanger" on it, though.