I have a parts motor that has five wires, and annother that has four. The one I have in my runner is 3. I guess that's why it's always a little hard to get everything running right.
The two parts motors have totally diffrent bosch set ups, and the running one is a monoplat. On most of them the blue goes to the coil, and there is a black for the ground.
I have a feeling that the grey maby might be for the lights yellow for the horn, and the greens are grounds for each of these circuts. You may have to check with your volt-meeter, starting with high ac voltage, and stepping down your range untill you get a reading, or at least a blip on the screen.
Post any of your findings, it'll help the next guy.