on the 04 si on the driver side is blue white and blue black. What is power and what is ground?

 

95% of the time black is ground. You got a friend at Best Buy or Circuit City or another store that installs radios and speakers, call them and ask. The other thing you can do if you have an aftermarket headunit, the instructions it came with may show the wires and what colors they are.

 

Nevermind I just remember that I had a Haynes just didnt remember whee it was at and i found it. Thanks anyways.