There is a plug by the passenger side head lamp that is not plugged to anything?

What is your question?

I would like to know where this plug is supposed to be connected if at all. My Uplander is registering as running hot although I just replaced the radiator. It seems to be fine until I get to about 45 to 45. Then the temp gauge jumps up. It drops back down when I left off of the gas and coast. I'm thinking the thermostat may need to be changed as well but this plug makes me wonder. It wasn't plugged in when I started changing the radiator and I'm wondering if it has something to do with my problems.