Freightliner HVAC Controller Fix

The fan speed switch on my 2005 Freightliner M2 acts up fairly regularly. The fan speed seems to have a mind of its own. It will change one speed up or down randomly. If I tap the fan speed knob, it will resume the fan speed it's supposed to be. I figured there were individual contacts for each fan speed. I learned that it's way more complicated than that...
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