On images of the real version you see below in the corner of the Aft Lower Window Liner’ a connector to which a curled cable is connected. On the other side, this cable is connected with a connector in the DV Window Armrest/Chart holder (Shroud)’. The curly cable is used for kept the window heating activated.

As a simulation I've used the ‘Aft Lower Window Liner’ and the ‘Armrest/Chart holder in my cockpit is also equipped with 2 terminals + cables. For the 2 terminals I have plugs used for connecting a hand mike with a CB radio.

The curly cables are for sale in an electronics store or via the Internet.

More information and images at the following link: http://www.flightdeck737.be/hardware/platform/window-liners/side-aft-lower-window-liners-capt-en-fo/