Does anyone know what this part does specifically? The wires have been cut from mine, so I assume it was malfunctioning, but it also doesn't seem to be required either.

This is a picture of what it looks like (just a random picture I found online).

Its an electronic load idle up solenoid. When you turn on your fan or put an electrical load on your alternator, this thing opens up and adds a little more idle speed

Don't need it, unless you getting wild with ICE. Even with Headlights, wipers, heater, stereo, etc on, rpm only drops 100 or so.