Might be difficult for people to know exactly what the wire is for. What doesn't function when you power the prop on? That might tell you where to look for an empty connection. For example: the eyes don't light up you look between the power and the LEDs, if he doesn't move laterally you look at the motor that turns that way, etc. Maybe a last minute stop into a Spirit store and look "up the dress" of one of these (if they still have them instore?) might tell you what you're looking for.
Sorry for the lame answer, but maybe something will click. Good luck!