The plug is under the center console stack. Pull on the carpeted panel at red arrow towards the sides of the car about 2 inches to unsnap the panel (same can be done in passenger side). Then slide the panel towards front of the car to release the panel completely.
Dig around (it might be taped to the floor) for a 4 pin/wire (3 pin if MY '97) connector. Here's an actual picture of the connector and a schematic:
(I made this one for someone who needed to discern which wire was which based on the plug b/c they were color-blind).
If you're not color blind, here's an easier schematic I made:
Or you could always just run a lead to the fuse panel are there are a number of switched and unswitched empty slots available there too.
Good luck
