First off, what is this part, and what does it do? It is making an ungodly buzzing noise that I'm sick and tired of, when the key is turned to run, and my other subie doesn't make that noise, so I'd like to fix it. I've traced it down to a wiring problem. I have photos at the bottom, but I'd also like to ask another question.

 

The wires for said part lead eventually lead into a black box underneath my dash about 7" x 4" x .5" or so, and is made of metal of some sort. There are two bundles of wires going into it, one going in, and one going out, I presume. I don't really care where the wires going out of it go to, but where does the bundle going into it come from? Or more specifically, where would I find the control for the part I mentioned earlier?

 

We are looking at the top of the engine from the back of the engine compartment, just to give you some perspective. The greenish blue thing is the back of the air filter and the carb right underneath.

I am not really familiar with it but I thought those were part of the IAC.Part of the emission control stuff?I am kinda stumped as well.I could just look in my book I guess.

The box under the dash you are talking about is the ECU I believe. This is the brain for the emissions system.

 

The device you picture looks to be a solenoid valve for the fuel evaporative system but I am only guessing. The device uses 12 volts to open a valve and that allows whatever is in the tubing to flow through the valve. I have heard of problems with this being caused by a problem with the alternator. To see if that is your problem try removing the leads to the alternator and then turn on the ignition. If the noise is gone then you need to change out the alternator. Be sure to disconnect the negative battery lead before working on the alternator. The main alternator lead is hot to the battery and will short if you contact ground with that lead. Make sure all the leads are isolated from ground when you reconnect the battery.