Topic: CB550 Headlight "Spaghetti" Help!

[davidru2]

Main headlight on my 74 CB550 stopped working.  I checked the headlight and it works, but not sure what the problem is.  There's so many wires behind my headlight it looks like electrical spaghetti!

All I know is that the ground works as does the light when I go direct to the batt., I also cleaned the connections and that hasn't helped.  I'm a bit confused as to what the blue and white cables even do.

Please help, don't even know what to look for here.

[mystic_1]

You've checked the headlight fuse, I hope?



White is +12v power to the low-beam filament, Blue is +12v power to the high-beam filament.  Green is ground, of course.

You should be able to measure +12V on one or the other of the blue or white wires, if not, start working backwards.

The headlight switch is powerd from the BRN+RED (?) wire that leads to the headlight dimmer switch from the fuse block..

If you have no power there, check for +12v at the BROWN wire coming from the key switch. 

Somewhere along the line you'll find the spot where you don't have voltage, but should.

Are the rest of the electrics are working properly?

mystic_1

[OneWheelDrive]

The good news is that you have what looks like a stock and very clean wiring harness. Get the wiring diagram and learn. 12v systems are surprisingly simple and those Honda engineers made the diagrams pretty easy to follow.

[CB650CPastor]

Green is ground/earth, blue is high beam, and white is low beam. Check all of the connections from the switch, clean all connections, clean and verify the switch is operational with a meter, verify fuse continuity with a meter, check wire continuity with a meter. That's all there is in the system. If you do all of that, you'll find the problem.

[davidru2]

I haven't, I wasn't sure where it was.  I'm going to look it up now --very helpful - thanks!

[davidru2]

The Fuse was the culprit!  The fuse box was hidden as the previous owner changed the location to make room for a new rectifier! 

THANKS EVERYONE !

[mystic_1]

Ah excellent.  Simple fix!

mystic_1

[evanphi]

FWIW, I ran into this exact problem the other day, and I know my headlight bucket's rat's nest inside out... It was ALSO the fuse and ALSO the last thing I checked!

New fuse... let there be light!

[PeWe]

Fuse should not blow without reason. I hope you have found out why when it can blow again. Hopefully correct fuse (number of A)