Want to know one of my little secrets to getting these sound boards to work on the block (system 11)??
Because system 11 use the relay so the same transistor can either drive a flasher or a relay we couldn't get them to work because the sounds would be firing every 30 seconds instead of just when the coil or whichever single item we wanted to trigger a sound. Took me a bloody long time to work this out and ended up being a very simple solution...
So you took the trigger off the coil that fired?