First off, thanks in advance to anyone that tries to help and puts up with my ignorance.

So yesterday I was out driving and started getting audio feedback on an onramp, then complete shutdown about a mile later. Everything came back on but it wouldn't start. Popped the hood and see that my secondary alternator cable I'd run had come loose. (Will be suiting from direct terminal clamp to ring terminal after this)

So with that happening (even though it doesn't seem like it actually made contact anywhere while pushing current) something fried. I'm not getting fuel (and possibly not spark, but thats a later matter) I've checked the fuel pump fuse, and interior relay so far, both were fine. I remembered while I was sitting on the side of the road with acc on I noticed some intermittent clicking noises coming from around the engine.

It was this guy
http://imgur.com/ok2iC1n

So, I turn the car off and back on and instead of the spirited (clickity-clickity-clickity-click) I normally hear before turning over I just got one muffled sad click out of it. Not sure what the part is, or how it's wired in there. What is this part anyway?

I'm also getting bad interference through the speakers whether the Head Unit is on or off, which changes in frequency according to what's on and what's off in the car. Has the same tone as a ground-loop fault. Now that itself could be due to rapidly going over all my connections on the side of the road but I'm thinking it may be picking up an incomplete/shorted/melted circuit somewhere.

So. What is this part? Where are the relays/fusing for it? What else should I check being this part is acting faulty?