Iv'e always been curious because I've been in many xjs's and it never seems to work/have a purpose. What is that oval plastic thing just above the glove box lock/handle/knob on the bottom of the curve of the dash? Is it a light? or what? Just curious because I noticed it again today and if it is broken I'd like to fix it whatever it is. I hope I'm explaining it well.. I can post a picture if necessary. Thanks!

 

That's the air inlet for the cabin air temp sensor. The sensor itself is a couple inches behind the opening in the lip of the dash and is connected to a long tube that runs down to the ventilation ducting behind the dash. The air flowing thru the duct creates a small pressure drop at the end of the tube so that air is pulled in thru the opening above the gove box and drawn thru the temp sensor. The sensor reading is used by the climate control to help regulate cabin temperature

Cheers
DD

 

Thanks Doug!