The other day I picked up a friend from the train and his bag hit my dash, i guess kinda hard. It knocked a wire from my sterio unit loose. So i took it out, reconected it, and now my a/c only works on setting 4!! What's goin on? Any incite would be great!
Thanks

 

I have the same problem. My A/C only works on 4. My mechanic says its my blower motor thats bad. You might have an electrical problem though.

 

This happened to me a couple years ago, its the a/c switch not the blower. The blower will go out eventually in due time but its not the blower..

 

The resistor block mounted under the glove box is either disconnected or has gone bad. The resistor block controls blower speeeds 1,2 & 3 Speed 4 is sort of like WOT - It by-passes the resistor block.

Your buddy may have knocked the plug out.

For people who's blowers only work on setting 4, replace your resistor block. It's mounted on the HVAC duct (quack quack) right after the blower motor. It's a small plug with about 4 or 5 wires on it. I believe one or two screws holds it in place. The part is about 30 bucks at your local Nissan dealer. Ask the parts guy to show you a picture of where it's located in the diagram. Really easy fix!