e39 navi radio wiring

Hi everyone,

I have a question about 2002 e39 original radio that comes with big screen navigations system. I have High power speaker to line adapter, there are four wires coming out of the adapter: (Right +) (Right -) (Left +) (Left -). I don’t know where to connect them.
Doest any one have a radio connector manual, so I can figure out where to connect those 4 wires.

Thanks in advance

You might try the12volt.com then scroll down the page to the BMW link, if there is a stereo link for your vehicle, it will be on the right side of the page. The link gives wiring colors and application.