This was all in a pm I sent to newtothegame to help clarify wiring and whatnot:
"So, first of all that link I posted for the LED's is great. $4.50 for 50 of them shipped in your color choice. Get some 1/8th inch shrink tubing for the connections, and I just used very small un-insulated butt splices from Napa to splice LED terminals to the wires, then slide up the shrink tube and heat it up to get it sealed well. Connect them in series, 4 LED's, no more than 4, definitely no less. You can parallel some if you want more than 4 LEDs on, but you need to have 4 connected in series. I connected 4 led's, negative to positive of the next LED, then neg to pos of the next, ETC. You have to use up 12v of power across 4 LED's, so each receives 3v. Again, if you want more than 4, just parallel the line by hooking pos to pos and neg to neg on one of your four.
These illustrations might help:http://www.theledlight.com/ledcircuits.html
Remember, if you want more than 4, at any point in the circuit you can connect more in parallel. This is done by connecting positive to positive and negative to negative of however many extra led's you need, but you must still have 4 led's connected in series or they all blow up, or don't get enough power. So to correctly do say, 11 led's, you might connect 2 in series, then on the third led in the series, split off and connect the extra 7 in parallel, splicing all positives and negatives together for 8 (7 extra +1 in the series) led's, and connect the last led in series.
I measured down 1 and 1/4" from the top wall, and 1" in from the top and bottom of the IC. I used a bit around 1/4" maybe and tapped my holes at those locations. I stuffed small rubber grommets I got from Napa (part number 770-1301 BK) into the holes. They have lips on either side of the hole, and a center just large enough to put an LED.
Pull a pos wire from your ACC. or + battery terminal to a switch, + off the other side of the switch to the first + of the LED, off the neg of that led to + of the next, etc until complete."
Feel free to ask questions. I just replaced the LED's because I believe under hood heat got to them. I put a dab of heat resistant silicone on the back of each one and they've lasted for about a week and a half now, so far it's better than my 3 days on the last set.