Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hello I will help you with your question,
It sounds like the blower switch is where you need to start if the switch feel has changed and you saw smoke there then it likely burned open.
The switch is part of the control panel so you need the whole panel, car-part.com has used parts that you can search for with contact information or if you want new http://www.nissanpartsdeal.com/parts/nissan-control-assy~27510-zw80d.html is one source.
Click here for service procedure
Please let me know if you have further questions