Help identifying wire's on premium radio

[bill meyer]

I'm trying to wire in a factory BMW radio (the model with the slider control) and could use some help figuring out a few wires. The plugs in my 1990 M3 are long gone, so everything has to be spliced in. I have identified the tabs for speaker's, main power, and Ground. What I need to find is the "always hot" wire. In the pic there are 4 wires coming out, yellow, white, white/brwn, blue/brwn. Any idea what they are?

Thanks!

[StereoInstaller1]

Bill, I suggest you download the ETM for the car that radio came from and compare the colors.

[AndrewBird]

ETM can be found here:

http://www.wedophones.com/BMWManualsLead.htm

[bill meyer]

Thanks guys!