When I am coming to a stop, at the exact moment the car actually stops, a sound "plinks" from the glove box area - like a rubber band is being snapped against plastic. Sounds like some kind of vacuum diaphragm or vacuum servo. I have not pulled the box down or off yet to look behind it, inside the cab. Anyone have any idea before I go digging? Only happens when the vehicle comes to a halt.

 

Check to see if the glove box light is broken and hanging down. It "could" make a sound if it's just hanging from the wiring harness.

 

Will do. Thanks

 

OK, I noticed today while already at a stop the "plink" sound. It may just be a coincidence when braking. Today it happened when I powered off the air vents. I have it set to ECON and adjust the heat up/down accordingly.

is there a flap that could be closing behind the glove box? Also, I notice if I power off the system, it still releases a trickle of hot air into the cabin.