2001 nissan pathfinder air not blowing out of vents by windshield

SOURCE: 2005 Pathfinder Heat Flow problem

I am having/had the same problem. My rear heater has not worked the last 2 winters, still trying to figure that one out. But I think I solved the front heat problem myself. The heater was blowing cold air while idling and hot air when the car was moving.

I jacked up the front of the vehicle, took the cap off of the reserve tank for the radiator, turned the car on and ran the heat (AC off) for 15 minutes. This is supposed to release any air bubbles in the coolant system and I did see air bubbles emerge as I was watching (this might be normal occurance, I'm far from a mechanical expert). Anyway, this did not immediately solve the problem, still blowing cold air as it sat there idling after 15 minutes. Dejected, I put the cap back on, lowered the vehicle and resigned myself to taking it to a dealer.

But a funny thing happened the next day, the coolant level was a lower (no leaks on the floor) so I filled up, and sure enough, when I started the car and let it warm up a little, hot air started coming out of the heater!!!

As far as my wife knows, I fixed the problem for the price of a bottle of coolant, so I am a hero...but at first I thought it didn't work. Here we are a month later and still blowing warm air and haven't had to replace any more coolant...the internet is a wonderful thing!

Hope this works for you, and I hope I can figure out my rear heater problem as well.

SOURCE: Would like to recharge my air conditioning on my 2001 nissian maxima that has 117,000 on it blows hot air when air conditioning is turned on.

You will need R134a, and a filler hose. Charge the system on the low pressure side, it should have a blue cap on the charge point.
Your filler hose will only fit the low pressure side, just in case the cap has been removed.

SOURCE: removel of altanator on 2001 nissan pathfinder

Disconnect the battery - both positive and negative terminals and remove battery from holder (better access that way). From underneath - remove the plastic shield underneath the front of the car. It is held on by a few bolts. Remove the upper radiator hose (some coolant will drain out). Also free the cable from the support bracket on the top of the platic fan housing. There is an overflow hose that is also clipped to the fan housing unlcip the hose and move it out of the way. From underneath, push in on the clips and the lower half of the fan housing will come out of the bottom. From the top - remove the two bolts holding the upper part of the fan housing and you should be able to work it out from the top. You should now have better visibility and access to the alternator. Loosen the belt tensioner (from below) and remove the belt. There are two mounting bolts on the alternator, a long one through the alternator and a second on the "dog ear" of the alternator. Once the alternator is free - you can get at the battery cable post and the other wires. The wiring harness can be removed by pressing in on the locking clip. Most difficult is the wiring harness support bracket. A short 10mm wrench can get to it. The alternator is now free but will have to be manipulated forward so that it sits below the fan. Once there - you can reach down from the top, and pull the alternator into the larger gap between the fan blades. While rotating the fan, bring the alternator around with it to the top and it will come out. To reinstall -- do everything in reverse. I recommend replacing the belt so you don;t have to do this again.