its right under the intake manifold, upper left of the oil filter( if you're looking at the motor from behind). yes you need to run a wire for it. what year is your car? the easiest thing to do is to get an EX harness from a civic that is your same generation (ex: 92-95 EX, 96-98 EX, 99-00 EX or Si) let me know if you need anymore help