If memory serves, the stock turn signal (on the front) uses one side of the dual element bulb as a running light, and when the turn signal is activated, it turns off the running light, and lights both segments for the turning. Hard to visualize, but I think when the turn switch is closed, the ground connection (the one shared by both bulb elements) is moved to the un-lit segment. Then the flasher part kicks in, and strobes the whole bulb.
Your aftermarket switch may just control the turn element, meaning it may not support running lights. If that's not a problem, then it should be a matter of wiring the switch through the flasher circuit, and from there to the appropriate bulb. Download the FSM from the home page of our happy little forum, and track down the connection for the flasher, the turn signal switch, and the bulbs.
Sorry I can't be more help, but I'm confident you'll get it to work.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
Locked
