What a journey this has been! After testing all of the components that make up this system, everything is working correctly and reliably. I was able to go back to a 5 pin relay since the Water Temp Circuit has its own on-board relay.
The system is adaptable to suit those who want warning lights, or those who just want sound. I updated the article but there is more to be corrected and updated in the coming days.
http://devestechnet.com/Home/WarningSystem#WaterTempFinal
