Help Id Wire Connectors

The one on the fan harness is for the coolant overflow. Ford sold or put on a cap that had the sensor built in. I know my 94 never had one but my 95 does. Definitely not needed. It only goes to the idiot light on the dash.

The black wire you have there is just a ground. Should be grounded out in front of the battery above the headlight. That whole bunch of wires there, the black and the black and white are the grounds for the computer and computer harness. I went through and soldered them all together and grounded the whole bunch. More grounds is better than less. I can get you a picture of what I did on my car later if you want