CJ:
What model Sony, and how old. This thread covers the current model Sony wires, and the help lines for Sony info! Radio Harness
You might also get more info at http://www.sonystyle.com/sonystyle/4784/5210/5272/5240/3942.support.default.html#
It has manuals and FAQ sections for their current models, including the wiring diagrams.
Hope this helps.

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E