I can see from the drawing the circuit uses a DPDT switch with common being the center tab.
In the inactive mode, the contacts are open on the top two contacts (N.O.) of the 2 internal switches.
No power to the LED lights in one of the internal switches and in the other internal switch, the top 2 wires
are not connected (NO) but the bottom 2 are connected (N.C.) putting GND to pin 18.
When the button is pressed (activated), then the center contact removes the GND from pin 18 and applies it
to pin 19 triggering the sound. At the same time on the other switch, the center contact connects to the top tab
(closes) and the light illuminates as long as you hold the switch in.
I guess you changed the 12v to the lights, to 6v power supply.
The 3v power supply has it's own function and should not be compromised or used for any other purpose.
As I see it the TRIGGER GND. for the sound board is coming from the 3v power supply to pins 18 and 19.
If 3v is getting to the sound board directly and the 12v is feeding the amp. directly, the 6v should go through
the PB switch to turn on the lights and active the sound, it is set to go.
You are correct about the lights. The lights Valor provided in his kit were LED that required 12v, but the lights that were already permanantly installed in my pack took 6v, thus the need for a 12v to 6v convertor.
Can you help me understand what you mean by having the 6v go through the PB switch?
I took some more videos to help troubleshoot because I think something is happening in the 6v side of things in dealing with power draw...
This first video has all that requires 6v getting it directly and not working:
This second video has only one light connected directly to 6v and still not working:
This third video has everything but one of the lights coming from the 3v convertor and everything working (which is weird and confuses me now):