red light on headlight and tach not working now

[oakbark]

Hello everyone out there I just bought a 64 cb77 and everything was working great when I recieved it but now the red light on top of the headlight doesn't light up and the tachometer needle no longer moves. Not too much of a mechanic on these bikes yet but can anyone tell me what I need to do to fix this. I haven't taken anything apart yet looking for some info before I open up that can of worms. Thank you Chris

[e3steve]

Welcome to The Forum, Chris; buckle up and enjoy the rollercoaster ride!

Have you checked the lamp (bulb) in the neutral light? That notwithstanding, locate the main motor electrical connections -- in the main harness, under a PVC sleeve and just to the rear of & above the motor -- and disconnect the light green/red wire. Then, with the ignition ON, ground the disconnected end that leads upwards to under the tank, and see if the neutral light comes on. If so, then you'll need to remove and open up the neutral switch (inside the r/h casing, just above the front sprocket), clean it out and re-tension the contact.

The tacho is mechanically-driven, via cable, from the l/h side of the camshaft.