Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
The black is a switched power and nearest place,electrically, to battery is at the ignition switch
Maybe I've not read the posts properly, but is your bike a CB550..K..or.. F wiring looms are different
The earlier CB550K had a 5 wire safety switch, its possible that the later CB550K3 had a 2 wire safety switch which was also fitted to the F model.Have you fitted a diode (as image) to the 2-way socket?
If I measure the red and yellow wire attached to the starter Solenoid it's 0v until I hit the button it goes 12v+ but nothing happens.