The Yellow Wire (Genuine Buddy 2007+)

GrantSR · Post by **GrantSR** » Wed Dec 14, 2011 2:27 am

I'm starting a new topic just to discuss the function of the voltage on the yellow wire coming from the stator. I figure it may help people in the future to have this entirely sussed out.

From the official Genuine wiring diagram: The yellow wire comes from the stator somewhere in the middle of the same coil that also supplies the charging system.

This wire goes to one pin of the voltage regulator. Can anyone say for sure which pin? I'd go look but it is dark and raining outside. Does anyone know if the regulator does any modification of this voltage or is this pin merely an input to the regulator?

The yellow wire also goes to the headlight by way of the high-beam switch. The other side of the headlight goes to the black wire which is also used as the ground for most of the circuits in the scooter. It seems odd to me that an AC signal goes to a ground that is used by voltage regulated DC circuits. Most electrical engineers will tell you that this causes fluctuations in the DC ground which can be bad for reliability.

The yellow wire also goes to the auto-choke which grounds through that big, ugly resistor to the frame.

In addition, our yellow wire goes up to the instrument panel to power two lamps, which in turn ground to that black DC ground wire.

Our yellow wire goes back to the tail lights, but the wiring diagram is unspecific as to what it powers. I'm guessing anything that is on all the time. Again, these lamps ground to the DC ground. But there is a light-blue wire that also goes back there. Does anyone know what that is for?

Well, folks, it looks as if that is it. The yellow wire brings 12vAC to a total of five circuits. If anyone could answer my questions about the regulator and how it deals with that 12vAC I would really appreciate it.

GrantSR · Post by **GrantSR** » Wed Dec 14, 2011 2:34 am

I would think that any LED replacements for any of these lamps would have to have their own AC-DC rectifier and regulator built in. However, since an LED is a diode after all, it could serve as it's own rectifier and only use the top half of the AC sine wave. I guess a really smart replacement LED designer would just put two LEDs back to back and one would use the top (positive) half of the waveform while the other used the bottom (negative) half for double the brightness.

Does anyone know if any of the LED replacements are designed specifically to handle the 12vAC nature of these Buddy lighting circuits? I know an LED designed for DC will work with AC but will not be as bright unless it is designed to compensate.

PeteH · Post by **PeteH** » Wed Dec 14, 2011 3:12 am

Blue wire is the hot side of the (LED) brake lights.