[kck3]

I recently picked up a 1971 CB350 twin. I am having issues with the headlight and am seeking some advice. The headlight is a sealed beam unit and it currently does not work. When I switch the low/high beam selector on, the tail running lamp comes on but no headlamp. I took apart the headlight and have three wires coming out off the bulb: green blue white. Which one of these brings power to the bulb? I know that blue is high beam and white is low beam and is green ground? Just wondering where I should start looking for power supply to the bulb.

 

[jayel]

your power should be the brown/white going in to the slector switch

 

[66Sprint]

First check continuity between white to green and then blue to green (checking filaments)... Green is indeed the ground.....IF both readings are contiguous, try running a KNOWN good ground to the green wire (jumper it to battery negative for instance)..... You do have power to the switch as the taillight works.....Black wire is the power (HOT when key is on) throughout the bike.....

 

[cpc]

personally, id say your first step would be to test the headlight with a 12v battery to make sure it in itself is not burned out....if your taillight is working, chances are the wiring for the headlight is ok, for being nearly 40 years old.....I re-wired my entire bike, and i ended up being able to get rid of over half the stock wires honda uses....now it runs 100% better, and i know whats what, and is done properly....only takes about 6 hours to re-wire the whole bike if you know what you are doing