I changed my thermostat housing but now my coolant temperature sensor doesn't wo

What is your question?

I changed my thermostat housing and I'm pretty sure I did it right (unless theirs anything special) but now the coolant temp sensor doesn't work and I even replaced that but still j have the check engine light and my gauge is at the coldest it can (temperature gauge) is it possible the wiring harness got damaged or am I looking at the wrong part to replace. I know older models have a separate sending unit behind the head. But it's a 97 so just seeking professional help.