It's usually a 7-pin or 4-pin connector tucked away somewhat, possibly near the fuse box or other wiring harnesses. A flashlight and some patience will likely be required.
Important Note: Before starting any work, consult your owner's manual. It might have a diagram showing the exact location and specifics for your vehicle. If you're uncomfortable working on your vehicle's wiring, it's best to consult a qualified mechanic.
