This is a part for 1998-2003 Ford Escorts and 1998-1999 Mercury Tracers.
It is a relay module that controls 3 things: the ac compressor, the fuel pump, and the cooling fan for the engine. Here's the funny thing though: one of those three things can be bad in the module, and the other two can be just fine. In other words, the ac wont work, but the fuel pump still pumps fuel and the cooling fan still runs.