I was about to try that but found that my wife changed the fan speed to 3 a couple days back and the system is still working normally. i am reluctant to try tapping or any other tests as long as the A/C seems to be working ok. One other thought I did have was for me to purchase a spare Control Module and have it shipped to Pizza Guy (if he is willing) to be checked and repaired if required. Then that unit could be held by him as a replacement for the next one (from the forum owners) that needs to be replaced (as this seems to be a likely prospect). Just a thought ...