Push the pin into the orange housing until you hear a slight click. Here, we have the water temperature sensor connector wiring completed. We put heat shrink on the wires after twisting and fed them through the firewall. Now we need to pin the ECU connector side.
One thing you'll notice when reading the pinout diagram for the ECU harness side connector is that there is only one pin location for temperature sensor ground, however if you have two sensors (one for water temperature and one for oil temperature), you will need to splice the two ground wires. Being diligent with this task is very important to prevent the splice from separating. We carefully soldered after giving the bare wires a clean twist, and we will secure with a separate terminal.
We crimped on a separate terminal to secure the splice (not provided, but easily attainable). We then added heat shrink over the spliced area.