Replacment Lewmar windlass motor wiring

[Upnorth]

I am replacing a windlass motor on a friends boat. The motor is the type with a common terminal and two 'M' terminals which are connected via a contactor to reverse the motor direction. On the wiring diagram the common terminal is shown as going to battery negative. However on checking the wiring with a meter the previous motor was wired with positive going to this common terminal.

Does anyone know whether this type of motor cares which polarity goes to the common terminal?