heater blower unit wiring

[growling]

I have a 53 2.0 HDI with aircon. My heater blower unit has packed up and got a replacement for my car, the part number 6441N4, however the power leads to the motor within the blower unit have a different connection. This is not a problem but coming off as a spur from the negative connection seems to be an earth lead with a spade connector. This does not exist on my original part.
Any ideas where I should connect it?
Thanks