i just did this yesterday...oem dc2 deck into an 88 civic.

I tried matching all the colors and the radio didn't work. all colors matched up except for the 12V switched. I connected yel/red in the chassis wiring to whi/grn on the radio harness. the oem radio asked for a code and worked properly afterwards.

http://www.installdr.com/Harnesses/HA-Wiring.pdf
in my case 12v switched from pin D was whi/grn.