Nissan Repair: 01 Xterra not starting, neutral safety switch, cold weather

Question
I tried to start my 01 xterra this morning and it would not start at all.   It would not even give that clicking noise that I would normally get if the battery was drained.  This battery is also about 1 month old.  The weather was a little chilly, which give me a reason to believe that it is giving me  this problem due to cold weather.  this has happened before.  As the day progressed, the temperature got warmer and when I arrived back home from work, I tried turning on the xterra and it came on with no problem whatsoever.  This morning when I tried it, I did try to get a boost but same thing.   One other seperate problem is that my ac does not work when I turn it to either 1,2, or 3 but it does work on 4.  Thank you for any help you can give me to try to find out what it is.

Answer
Marco,

Sounds like the neutral safety switch if you get no click at all.  Otherwise, check the electrical connection under the hood at the battery.

The blower resistor needs to be changed as it is blown.  Under the dash on the passenger side on the blower case.  Buy a new one and you will know what you are looking for.  A couple of screws and it is plug and play.