Nissan Repair: a/c fan cant turn off and adjust speed, nissan sentra, light probe

Question
Hi, i have a 08 nissan sentra, when i turn the key on ro start engine, air blows out of vent right away, i can not adjust the fan speed, and the "off" switch does not work at all.Can you pls tell me what's wrang with it and whick parts has to be replaced?
thank you so much.
thomas

Answer
Hi Thomas -

Could be a couple things - fan switch or the resistor, located against the firewall engine compartment passenger side. Usually it extends into the ductwork. The switch, obviously would be behind the dash.

To diagnose requires the use of a 12V light probe. If you have one I can give you basic instructions.

Hope this helps -
aloha
calvin