I have a '90 Jetta. I am installing a custom stereo (Sony) with an open ended wire harness and the wire scheme for the speakers is different. The radio is powered but I can't wire the speakers. There are three connectors in the back of the factory stereo, power connector speaker connector and external control connector. The external control connector is a little larger than the other two with 10 slots instead of 8 and the "speaker wires" are in the external connector slot instead of the speaker connector. There are six wires in the conector for 4 speakers and two are sharing a slot. So five of the 10 slots in the external control connector are occupied. Also I found out slot 3 on the power connector is for and active speaker control is that part of the actual speaker wires? I've connected the speaker wires several different ways and I can't get any sound.

 

Bently? I don't know what that is.

 

its bible of volkswagens

 

The ground wires for the speakers could technically be shared, not that I would do it that way, but German wiring is kinda fucked up.

if you want to test the wires out to figure which ones go to which speaker you can touch them to a 9v battery ant the speaker those wires go to will make a pop sound.