Cozza

Hi Guys This is my first post I will try not to cock it up :( I have a 2001 2.2 HDi Estate with a Clarion standard radio, I want to fit a Clarion CD Changer PU-2145, this unit has a blue oblong plug on the rear (12 Way I Think). he radio has a fully populated rear with no spare ways, I have read all the other posts regarding this subject and I have found an empty connector under the drivers seat, this plug is a black 6 in line connector, the middle three are thicker for power I assume, is this the connector for the changer, why is it only six way. Do I need an adapter, what unit was fitted as standard? How can I Make My Clarion Radio CD work / interface with my Clarion Changer.... I'm sure someone knows, Thanks