A little background first-
Just bought our first home (Im 21, girlfriend is 20),
Congratulations. You're getting a much earlier start on home ownership than most folks do. That is a good thing; and if you treat the place right, this investment will pay off in spades later in life.
house was built in 1928, the garage is old but definitely not 1928.
Has a single electrical line going underground from the house to the garage, which comes into a switch, and 4 outlets. Then splices off into 2 other switches, (1st switch controls 2 lights on the ceiling, 2nd switch is the light in the "attic" and 3rd controls a large dusk to dawn light on the front, outside.)
You didn't mention how old the electrical installation is, as compared to the garage itself or the house; but based in part on your later comments, I'll wager that it was a DIY job by a previous owner, which probably didn't meet code even back when it was done. If you make significant changes to the electric service to that garage, you will near-certainly need to bring it ALL up to current code.
The inside is unfinished, and I would like to finish it with drywall.
And you should insulate "to the max" BEFORE putting that drywall in, even if you don't think you "need" it now (due to not currently having heat or A/C in the garage). But we're getting ahead of ourselves, because the electrical system needs to be sorted out before EITHER of these jobs.
I will be using regular 4' fluorescent fixtures (x4) as lighting which will be easy to wire in place of the current 1 bulb fixtures.
I'll reserve final judgement until I know more details about the garage -- such as its dimensions: Is this a single-car garage? Two-car garage? More? What about ceiling height? That dimension in particular will have a large impact on the lighting scheme you'll want to use, and its effectiveness. You mentioned "attic"; is there a loft? What is the current access to it? And what will it be after you slap up drywall everywhere?
But more immediately: Don't count on reusing ANY of the existing wiring. With open-frame walls & ceiling, it's child's play to run new stuff; and the cost is not onerous. So unless the existing wiring is both a lot newer than I suspect it is, AND installed perfectly, AND by some miracle in exactly the right places vis-a-vis what you REALLY want to do in that space... Then odds are it will be simpler and easier to just start over from scratch. IOW, don't let the tail wag the dog!
I have a fridge, and would like to install a nice stereo system which will be my 2 big draws, and will soon be getting an air compressor, and TV out there.
Unless you are going to insane levels of overkill on both devices, neither the fridge nor the stereo system will be anywhere near the biggest draws you're likely to have out there. For example, even a relatively modest medium-size compressor can require a dedicated 30A/240V circuit, all by itself.
Before you can accurately assess just "how much" electrical service you'll need in that garage, you need to figure out what tools & machines you will (or might someday) have out there. In order to do that, you need to define what sort of work you'll be doing in that garage, and by how many people at a time. Answer THOSE questions in an accurate and detailed manner, and the rest will almost automagically fall into place.
My question is- I want more outlets at least 2 on each wall but I feel that I would need to run another power wire out there to disperse all the power?
As mentioned by "pattenp", if this is a detached carage, you CANNOT have more than one power line running to it from the house, period.
It would be going from the 4 outlets right inside the door to 2 sets of 1 outlet plugs on the sides and back wall.
You could do it that way, BUT... The typical recommendation for general-purpose 120V outlets in garages (at least for garages used for more than simple parking spaces) is to have one double-gang box every 6-10 feet, all around the perimeter of the space (except where the vehicle door prevents that, of course). Each of those boxes would be fed from TWO separate 20A branch circuits, each of which would connect to ONE of the two duplex outlet devices (i.e., four sockets total) in that box. In a small garage, especially one where only one person will be working, the same two 20A circuits can feed all the outlets, daisy-chain style. But in any case, the FIRST outlet in each circuit must be a GFCI type (if installed correctly, this will provide GFCI protection for ALL the outlets). Notably, this scheme puts two 20A circuits within 6-10 feet of wherever you might be working at that moment, so that you can run multiple tools without risking overload of a single circuit. The garage door opener(s) go(es) on yet another 20A circuit, regardless of whether it/they are hard-wired or plugged into an (usually ceiling-mounted) duplex outlet.
What are your suggestions? I would like to keep this all a DIY project, I can easily add the sockets and lighting, but im a bit intimidated when it comes to running more power out there
As mentioned previously (and by others), it is near-certain that you WILL need to run a new feeder from the house's main breaker panel, out to a (new) sub-panel in the garage; then install your branch circuits as required, fed from the sub-panel.
This also raises the question of the house's existing main breaker panel... Describe it as fully as you can, both in terms of what it is (make/model, total load capacity as defined by the main breaker, number of branch-circuit slots both currently in use and available for expansion), and where it is located relative to both the house and the garage. How long will the cable run from this panel to the new sub-panel be (AFTER you account for all the ups & downs and zigs & zags!)?
This might be a "noob" question, but what do you mean by having enough service out there? Its just a regular 120v line, from what I remember, the wire coming in looks just like the typical wire you see going into sockets in the house.
There is some not-so-hot work done in this house, the garage wiring being one. The wire comes up from the ground, then up the foundation slab, and under the garage wall up to the socket and switches.
That's yet another reason I'm betting you'll need to rip that out and start over.
Quite beyond the VERY questionable-sounding installation, if it really is just standard NM-B (a.k.a. "Romex") cable, which some hack threw together as an el-cheapo "quick & dirty" way to get some electric in the garage, that is not at all appropriate (or safe!) for direct burial, regardless of the load. And even if it really is proper UF-B Direct Burial cable (cf.
http://www.southwire.com/products/type-uf-b-direct-burial-water-well.htm), if it is not MUCH larger than what you'd find used for typical interior light-circuit wiring, then it is surely inadequate from a load current standpoint anyway.
But to attempt an answer to your question about "having enough service"... I'm betting that "similar to interior wiring" cable is
at most AWG 12, which is good for
at most 20 amps. But as alluded to above, your needs will surely be far beyond that. Even a relatively modest "home workshop" garage usually calls for at least 60A service; and 90-100A (hence the mention of 2-2-2-4 MHF) is a very prudent upgrade from that, which will provide a modest amount of "future-proofing" for very little more money.
Ill try to get some pictures tomorrow. Im not sure if there is a breaker (Id imagine yes, but haven't checked) that controls the garage or not.
There damned well better be! The more ominous question is, is that breaker dedicated to SOLELY to the feed to the garage? If there are ANY other loads (such as stuff within the house) on it, then that is yet another reason to abandon that existing feed to the garage, and start over.
I think running more or rerunning the power going out there will definitely be left to an electrician, I know I could easily add the plugs and lights myself, like pepi said, I can kill the circuit so theres no power running out there while I work.
I'll echo "theoldwizard1"'s comments on this. You may be able to save a significant portion of the cost by doing some of the "grunt work" yourself. If you are reasonably "handy", it's not all that difficult (tho' the digging can be, if you don't have the right tools). Install the sub-panel; rough in all the branch circuits; dig the trench (you'll probably want to rent a trencher for half a day for this), and maybe even run the feed cable from the general area of the sub-panel back to the general area of the main panel (leaving plenty of extra wire at each end). Then have the pro look over what you've done, fix any mistakes, and do the final connections. Some pros will not want to do this sort of job; but many will (especially in this economy -- at least assuming you're not in some area like the Jersey Shore, where ALL the trades are booked solid for months to come with reconstruction work).
