Post by
EdBwoy »
https://forums.nicoclub.com/edbwoy-u213758.html
Thu Nov 02, 2017 6:59 am
Hopefully someone comes along and tells you exactly where it is, if there is one. I can't remember seeing one when I had my qx4.
Meanwhile, maybe the audio section of the factory service manual (linked below), will help you locate it and also troubleshoot the issue.