My aftermarket amp can take these signals into the RCA jacks. I have the wiring info on the G so I'm all set there.

As a test, I cut open some old Stinger "twisted" RCAs in the middle where it becomes one cable, and saw four tiny wires running through it (white, black, red, yellow). How do I know which color in the RCA is L or R and + or -? I plan to cut open some Rockford RCAs for the actual install (if that matters.)

 

Use a multimeter or a test light to run a current through each wire and see where it corresponds on the RCA end. The + post is in the middle of the RCA and the outsride is the -.

 

well if you cut up the end you're not using straight up to the connector, you can probably see which is which. the black and white will be the grounds for the red and yellow. So if you cut up the L connector wire and see that it's yellow & black... That's assuming you don't need the other side of the connectors, i guess.