Since you are asking about a fairing, I assume that you have a Vaquero or Voyager? There are accessory connectors in the left side of the fairing that you could probably use.
Here is a link to a site with service manuals for either one: Kawasaski Service Manuals. It has directions for how to remove the storage box on the left side to get to the plug. It's kinda tight in there, but you may not have to take the fairing off.
Here is a link to a site with service manuals for either one: Kawasaski Service Manuals. It has directions for how to remove the storage box on the left side to get to the plug. It's kinda tight in there, but you may not have to take the fairing off.