Chris here is the diagram

i cant remember if we looped over from the 12volt supply on one relay to the other.

but hopefully you get the idea from the pic.
all you need to do is put another relay in which is switched on by your switch. you can hook the relay contacts into the wiring for the semaphore coils so that the power is isolated to them when the relay is on or off.. it is your choice... just choose either NO contact or NC.
good luck...
let me know if ya need a hand.