OK OP my only question; do you have 2 (two) RCA inputs or one?
If you have only one pair or L/R RCAs add a second set. Cut the wires and leave pig tails on the original switch 1/2 - 1" long, from the input RCAs
DON’T cut them to short.
You need THREE dual poles and a two position toggle switch. The center 2 poles is the feed for the two pigtsils you left on the original switch.
The other two pairs of RCAs (L/R) goes to either side of the feed wire poles (center).
https://www.littelfuse.com/~/media/images/technical-resources/commercial-vehicle/switch-pole-throw-d...
You can have an OFF position by adding a 3rd center throw or it could combined both A and B positions (not usually a good idea)
So
A or B
A off B
A both B
Regards
If you have only one pair or L/R RCAs add a second set. Cut the wires and leave pig tails on the original switch 1/2 - 1" long, from the input RCAs
DON’T cut them to short.
You need THREE dual poles and a two position toggle switch. The center 2 poles is the feed for the two pigtsils you left on the original switch.
The other two pairs of RCAs (L/R) goes to either side of the feed wire poles (center).
https://www.littelfuse.com/~/media/images/technical-resources/commercial-vehicle/switch-pole-throw-d...
You can have an OFF position by adding a 3rd center throw or it could combined both A and B positions (not usually a good idea)
So
A or B
A off B
A both B
Regards