I just looked it up again in the service manual and this is called the Water Temperature Switch. This is in addition to the Temp Sending Unit.
There is a threaded end on the switch that screws into the fresh water pump. On the exposed end there is a wire that connects to it. I busted this wire off, but the way that it was connected is not typical like a ring terminal. It's like the end of the wire was attached by pouring plastic on top of the switch and when it solidified, it was stuck. Maybe I am over thinking this is just a type of soldering that I haven't seen before.