Engine coolant temperature sensor wiring diagram needed?

I broke the connector for the engine coolant temperature sensor. I was going to replace it so I had to cut the two wire one was black the other yellow. I know the yellow is like the power I guess, but when I got the other plug from the front fog lamp wiring that was never used. The wires were purple and light green. So, I hooked up the light green to yellow and purple to black and the gauge never reads over 140 on dash and scanner so I switch them and it read normal but kept going up down just a little thing is the gauge reads normal temperature like 200 when I haven’t even started car yet just with key on.