Headlight Relay

[bufallobiff]

I've joined this site because my good friend who actually owns an XS 11 won't do it. I've got a @3&=% GS 850 G with similar technology and he seems to think that they must be all the same. Anyway, here's a question. We spent the good part of Saturday trying to figure out why his headlights and brake light wouldn't come on as well as synching the carbs. His bike is a '79 SF. We found the problem with the headlight at the Fuseblock (original) and rewired that with separate inline fuse holders. After removing the seat more times than I'd like to remember, we found the brake light problem at the "light checker" module in the six pin connector. Having a motorcycle of almost the same vintage, I realise that corrosion sets in and connections aren't what they used to be. To my way of thinking, Yamaha made the lighting circuit just a bit more complex than required what with light checker units, reserve lighting units, etc. Anyway--to the question. There is a yellow wire eminating from the stator straight to the headlight relay supplying power to it once the engine has fired. The white wires are carrying the AC volts to the rectifier. Where does the yellow wire get its' power?

[3Phase]

Biff, the Yellow wire is the Neutral wire from the stator. It has roughly half the voltage of the three White wires.

[bufallobiff]

My stator puts out roughly 90 VAC per leg. I'm assuming that it should be somewhat equivalent to the XS. That would be 40VAC on the neutral to the relay. Am I close?

[3Phase]

My stator puts out roughly 90 VAC per leg. I'm assuming that it should be somewhat equivalent to the XS. That would be 40VAC on the neutral to the relay. Am I close?

Your own personal stator, Biff, or the one on your XS?

But, yes, roughly half the voltage. The XS11 stator is wye wound with the White wires on the outputs and the Yellow wire at the common center of the wye. I'm sure you know how the regulator/rectifier handles the 90 VAC and how to test it.

[bufallobiff]

I'm somewhat familiar. Our problem hasn't been a charging system problem. So far it has been old corroded connections. I kept looking at the schematic with the yellow wire going to the relay coil wondering where it got its' 12 volts DC. We checked the relay with 12 volts and it operated so I assumed the yellow wire delivered 12 volts DC. I guess there's no reason why AC wouldn't do the same thing. I appreciate your explaination. Even though we seem to have everything operating again, the yellow wire puzzled me. Now I can sleep. Thanks again..