Wiring a spotlight??

I've recently installed a Unity - Spotlight on my '94 crown vic. I've tried putting the wire into many different fuses and even to the battery, I'm 100% positive that the bulb and everything works because i've tested it before with a 9 volt battery. So my question is, how do I wire the spotlight into the car?

How did you hook it up to the battery? Step by Step. Also I would check the spotlight again just to make sure it works because when you go stright for the battery anything will work off of it.