Anonymous wrote:The vents go to a in-line fan, which controls the air speed in the vents. But the fan is usually pretty far down into the ducts, just past the heater core / AC exchanger / blend doors and just ahead of the directional air doors that divert air to the selected vents (dash, floor, windshield, mix).
They're VERY difficult to take apart (you usually have to remove the dash module) and its expensive because of the time involved.
You COULD try wrapping some duct tape sticky side out around a "flex-shaft grabber tool" (search it) and see if whatever you dropped will stick to it. It's a long shot, but I'd try it.
Also, get an endoscope camera tool (search it) and stick it down the vent and see if you can spot it.
Thank you very much! I'm going to try those suggestions. Do you think the thing can be clattering around on the fan and sounding like it's coming from under the hood? And is it dangerous to leave it down there? Thanks again!