I am considering buying a tuner module and an adaptor not to loose the steering wheel funcionality of the Clio, but because of the weakness of my country´s currency I believe that , at least for the time being I need to look at other options.

The one and only option that comes to my head, is to connect the empeg to the Aux-In of the actual radio (head). Now here is where I need some guideness from you guys, the head is a Blaupunkt CD31, and the Aux-In has the following layout:

C3 (see attachment)

13 nc
14 nc
15 permanent +12V
16 + 12V
17 Bus - Masse / GND
18 AF - Masse / GND
19 Line In L
20 Line in R

Can somebody help me understand the difference between 15&16 and 17&18? I need to find the correct adaptor or get someone to do it, but first I need to understand how the installation must be done.

James