993 window in 965 help?

[Porschephd]

I have a 993 Window in my 965 with the third brake light mounted on the glass. Who ever did this conversion never finished it and I am trying to complete it. As it looks there are 3 leads, positive and negative to the defroster and a third positive directly to the 3rd mounted brake light. It would appear that the ground for the light shares with the defroster. Can anyone confirm this? The 964 carriers two power leads and two grounds and seems that the 993 window uses only one set and a jumper wire soldered to the window.

Before I go shattering the glass can anyone share what they may know or see since I can not confirm 100% since I didn't put the window in.

Thanks