I suspect that it is like Bill has said, and the Yellow and Green wires allow the fan to reverse directions.

Might be a good idea if you eat a lot of beans and brussels sprouts not me


David Colter
pics * 1954 wrecker * [color:#009900]1948 Chevy 1-Ton[/color]
No act of kindness - no matter how small - is ever wasted ~~ Aesop