Motorcycle Repair: Turn signal indicator, brake warning light, dual filament

Question
Hi Bill.  I have recently purchased a 1985 CB650SC Nighthawk, and the bike runs great, with no real issues.  My only problem is that the right turn signal indicator on the display stays lit up all the time, and the left one doesn't come on at all.  The actual signals all work fine.  Also the light indicating that the break is on doesn't work.  Any help would be appreciated.

Thanks,

Matt

Answer
Matt,

http://oldmanhonda.com/MC/WiringDiagrams/CB650SC.jpg
This may or may not be your specific model, as there were some OHC 650SCs as well as the later DOHC versions, like yours. However, Honda wiring is pretty much the same, especially in areas like lighting.

The front signals are supposed to be ON all the time, as running lights, so probably you have a bad bulb in the left side. They should be a dual filament 1157 type of bulb. The running lights normally go OUT, when you select HI beam, though, to route extra current to the high beam lamp circuit.

I'm not sure about your brake light question. Normally, for later model bikes, the brake warning light, if equipped, is for a warning that the bulb has failed, not that the brake light has been actuated each and every time. That would get pretty annoying, while riding all the time.

Always check the bulbs to see if they have failed or not, before doing heavy-duty troubleshooting.

Bill Silver