Heating 3 position diverter valve?

I wonder if you could assist me with a problem I am having with a replacement part I bought? The part in question is a 3 Position Diverter Valve from Honeywell.
I have just got round to using this and went to fit it and noticed that this part has 6 wires whereas the original part had 5 wires. The question relates, I think, around the brown wire. The original part is a Honeywell 40003916-003 (Alternate Number is V4073A1039-6). This has 5 wires - Orange, Grey, White, Blue and Green/Yellow. The part I have is a Honeywell 40003916-001 which has 6 wires - Orange, Grey, White, Blue, Green/yellow and a Brown wire. I am not sure where to connect the brown wire. Any help of this matter would be gratefully appreciated. Barry