My '76 CB550F has two electrical problems. One, the starter switch isn't working. Two, the headlight is not working.
The solenoid is working, when I run juice directly to the two wires on the solenoid it hooks up and turns the starter over.
I ran a line from the black wiring in the harness directly to the headlight and it works.
The starter used to work "sometimes" and the headlight always worked before I took the bike completely apart. It took about nine months for me to get around to all the work I did on it (new pistons, rings, valve job, repainting the frame, rebuilding the front brake caliper etc.) and now the switch doesn't work anymore. I am guessing that the starter switch died of corrosion or lack of use.
I took the starter switch apart in a last effort to get it working and looked at the wires, then looked at the manual and followed the wires. I think I have them figured out and thought I'd share this info with others.
There are three wires attached to this starter switch. The black/red powers the headlight. The black is the hot lead (power coming in). And the yellow/red is for the starter.
People mention how the headlight turns off when the starter button is pressed and I am picturing a relay or some other switch buried under the tank or near the airbox. Well the way (I think) it works is simpler than that.
The starter button is connecting the headlight (black/red to black) when the button is not pressed. When the starter button is pressed, the contacts in the switch move over and connect the black to the yellow/red and hook up the starter. While it's connecting to the starter it's not touching the headlight contact.
Since my two problems are related to this switch, I think I will buy a new one.
Anyone want to add to this or correct me if I'm wrong? I am no electrician and it took me awhile to figure out how I think this works.
