I might post a seperate thread on this, but what is the best way to wire these bad boys up? I want them all on one switch, but I know that 175 watts of lights is going to draw some juice. I'm no electrical genius so any insight would be appreciated.
I might be able to help a tad here. I have about 35 years experience with electrical systems and can help with sizing, etc.
I'm guessing those are HID's and if so there's going to be a couple of things to keep in mind...
1) HID auto lamps usually have a 'pulse' start, meaning that although a normal HID lamp will take about 5 minutes to slooooowly get up to full brightness, an HID automotive lamp usually starts out at nearly full brightness. The electrical system essentially gives the lamp a heck of a whack of juice once you first toss the light switch on so it's a good idea to make sure the switch and wiring takes into consideration the pulse values shown in the installation instructions, assuming that a pulse is mentioned.
2) Distance between your electrical source and the lamps is a killer as it equates directly to voltage drop. It might seem like a tiny issue but that lamp is going to require a specific amount of wattage in order to light (and stay lit). If the voltage is significantly lower than the @ 12v required it will simply consume more amperage on the circuit which will pop fuses and overheat wiring, etc.
As a general rule of thumb, here's what you're looking at:
5 x 35W fixtures will consume 175W plus roughly 10% to account for the parasitic loss from the HID ballast. Let's just say that you're going to have an actual load somewhere around 192.5W or for round figures, 200W.
200W divided by 12V will give you your amperage draw which in this case will be about 17A, ballpark. Figure a 20A fuse will cover it.
20A wiring is size #12 copper. For good measure I'd bump that up to #10 copper in part because you're going to have some voltage drop based on the distance to the lights and in part because there's going to be a pulse on start up that will be better with less resistance in that circuit. A larger conductor will help reduce voltage drop issues.
You're on the edge. #10 copper wiring is good for 30A but while you're sorting this out make sure that your light switch is rated at 30A, minimum, and that any other pieces are rated at at least 30A as well (like any kind of bussing you use to tie these circuits together, etc.). A light switch rated at say, 15A would in this case be a fuse.
The above sizing should work assuming your pulse load isn't too long or too big. If you have trouble getting this circuit to hold the next option would be to go with a relay (if the concept is sketchy, think of them like a contactor or better yet, a big switch with a high amperage rating that is told what to do by a smaller switch with a lower amperage rating. These work a little like my marraige. The little switch tells the big switch what to do and it happens... or at least it better!).
In this instance you actually have an advantage being in FBX and that is that with cooler outside ambient temps your exterior wiring will be more efficient than it otherwise might be and therefore load losses will be lighter than they might otherwise be.
Holler if you've got any questions or if any of this babble didn't make sense, and thanks again for the heater. I've got it completely taken apart and partially rehab'd now. I very much appreciate it!