The vent is located on the top of the dash, in the center. To get to the sensor (thermistor) you will need to access it from the glove box area. Remove the glove box (pushpin fasteners). There is a foam tube that goes up to the sensor. Often the foam is dry rotted and gone. This tube draws air in across the sensor. There are wires with a connector under the dash. The plastic vent is two pieces, and has a part that comes off from the underside. Don't try to pry the louver top part, it has to come apart below before it comes up and out. The plasic part holds the sensor, and the air tube comes in on the plastic nozzle. I replaced my sensor (got it from Fastlane above). I used clear plastic tubing from Home Depot to replace the foam tube.