What is this? Is it supposed to be hooked up?

 

I believe it is part of rad fan control. It keeps the rad fan running after vehicle is turned off to help stop from coolant boiling over. Usually people disconnect it because when it gets defective it keeps fan running and drains battery. It should be connected and/or replaced to insure trouble free operation of vehicle

 

I wondered if that's what it was but don't see any wiring harness going to it, or any wires anywhere near it....guess maybe someone who has schematics could help with the wiring...Thanks

 

3rdit could be a usedd fan motor and the one they put n was different and yours originally did not have one

 

It is engine cooling fan resistor, connected to medium speed fan control relay.

 

Where might the medium speed fan control rely be at so I can get this hooked back up?

 

The fan control relay besides the resistor is missing in your photo.