Hi,
Here are the connections for a Symphony the picture shows the blue mini ISO plug.
The wire colours are in the box on the right..
The hand written connections are for the CD changer 10 pin plug..
If you look carefully at the changer plug there are numbers in each corner, so you can check the wire colours.
What each wire does is as follows..
KB = pink/black = cd changer audio L +ve
YB = yellow/black = cd changer audio R =ve
B = black = cd changer Earth
BK =black/pink = cd changer audio L -ve
BY =black/yellow = cd changer audio R -ve
WRY=white/red/yellow cd changer K Bus
PK = purple/pink = cd changer permanent battery feed.
Check all these connections..
Hope this helps..
Dave T