My lowbeam headlight for my civic is not working. However, the highbeams are. Is it the fuse that burned out for the low beams? If so, which fuse is it? There's two fuse boxes, one under the hood and one inside the car on the driver side. Is there a separate fuse for the high beams and low beams?

Not sure about the newer Civics, but the older ones (say around 1990) had 4 fuses for the headlights 2 X high, 2 X low). What you've probably done is blow both low beam fuses due to startup draw of the HID ballasts. Look on the Honda forums and search for fuse box layout for your year. Once you find the blown fuses, INSTALL the relayed headlight harness and put new fuses in the box.