[Gregski]

well after some trial and error I figured it out, and in doing so I can now explain why after wiring up all those car radios to house speakers back in the 80s still has me confused to this day

Red - this is switched power
Yellow - this is speaker wire for one side (L or R I forget which)
Black - this is ground speaker wire (don't matter which side)
Black - this is ground speaker wire (don't matter which side)
White - this is speaker wire for the other side (L or R I forget which)
Black - this is ground for the radio

What had me confused is the yellow wire, I thought it was also a power wire, but you got to remember back in the early 80s this radio had no pre sets, it had no memory, it had no clock, so no need to keep a constant voltage, so the yellow wire was simply the other speaker wire, I kept scratching my head going how do they get stereo out of two black wires and one white wire, and then I tried the yellow as a speaker wire and whalla we had tunes

but I must say I like the simplicity of this box, red = positive, black = negative, there are no yellow power wires, there are no blue tooth jobies and antena retractor wires, and cancel the radio while on the phone crap, etc...