I looked at those wires and they are the same red/white in color and i believe that lead to the jamma harness?
Just on the JAMMA harness there will be only two wires for audio.....
One is the + (pin 10 on the parts side)
One is the - (pin L on the solder side)
(this is mono)
So if you are trying to connect RCA style cables into that then the shield for both cables will go to the - wire ....... and the main conductor for both cables will go to the + wire.
But you need to verify exactly how the cabinet is wired FROM the amp TO the JAMMA harness first.
Since it appears to be a stereo amp, but JAMMA is mono..... I would
think that the two Red/White wires going from the amp to the JAMMA harness would be tied together somewhere. This is what I'm trying to verify.