Just bought a 97 5spd that is close to mint only issue is while test drive it was raining and the front window was fogged and wouldnt defrost noticed only hot air coming from main front vents on all settings has digital climate. How do i fix this what do i check 1st?

 

For defrost to actually work on the windshield, the temp has to be variable from cold to hot, the air blows directly on the windsurfer and not out the AC vents or floor vents, and most importantly, The AC system has to hold a FULL charge of the appropriate Freon with NO leaks. The belt is the same one as the alternator, so if the battery isn't dying, the belt is working. If all the air is pointed to where it needs to be, Your AC isn't working as it should..... Just blowing.

 

This would have nothing to do with the a/c . I have no air at all blowing from the defrost vent on top of the dash. Air only comes out the main vents that blow on the driver by radio etc. Its an issue with the blendoors but not sure if this was common easy fix or not

 

If you have no control over where the air comes out and it's STUCK on the AC vents, your Mode Motor Actuator isn't working anymore. Common after all these years!. It's located above your gas pedal on the right side, mounted to the HVAC system box. Most likely this part number, BUT TRIPLE CHECK before you order one.: Nissan 27731-40U00

There's a process to diagnose what has failed in the FSM you can download from here, using a sequence of buttons on the climate control to self diagnose. Look that up.

And BTW, WHENEVER you choose the defrost option, your AC compressor always gets turned on to remove the humidity from the air blowing on the windshield, HOT OR COLD, which is why it dries. Heat only, takes a LONG time to clear it up. So it can be one of the possibilities, or the other, and sometimes BOTH, when the defrost leaves the windshield wet and cloudy.

 

I have heard about the AC taking moisture out of the air but somehow I thought this was only on fancier vehicles than the 4th Gen - mind blown!

I guess this would explain why whenever I start up from cold and turn the defrost on I hear a squeal of something starting under the hood: it's the AC. My condenser core is on its way out, with the aluminum fins flaking away. When it dies does my defrost system go with it?

 

Once you lose your AC charge from a leak anywhere in the system, it will be CONSIDERABLY less effective, especially on days when precipitation is ruling the skies. Heated humidified air gets closer to steam, rather than dried out! And you just might be cursing up a storm when it's bad and you have to get somewhere quick. Too bad for that pedestrian!

 

The mode door actuator is located Just above the drivers gas pedal on the hvac box. You will need to verify how many pins it has first. If it's digital its likely a 10 pin which is similar to infiniti. I just went though this with this my 95 GLE with digital control. The motors get weak or the worm gear crack's (Pictured). The actuators listed for sale in my case at least, were not correct for my 95 at any parts store I could find and non existent aftermarket. But what I could easily find in the mean time were replacement dc motors on Ebay for $3.00 (RF-370C) is what I used I fix my OEM one. Weeks later I did eventually find a OEM brand new NOS one as well which is installed now.. PART: 27731-40U00 pics below are of the motor and the inside of the 10 pin Mode door actuator of a 95 GLE with Digital Climate controls. I have 1 left. Lmk