[Telboy68]

2019 Nissan Pathfinder S no aftermarket mods. What happened is I am able to change the mode on the control panel, I hear the fan and it changes speed when I adjust but only a little bit of air comes from dashboard vents and when I change mode it does not change. No air at feet or defrost. I changed the cabin air filter and still the same. Can anyone help me with how I can troubleshoot, it is just out of warranty 6 months ago. Any help is appreciated.
Thanks

 

[VStar650CL]

The inlet for the HVAC is located under the plastic cowl cover on the passenger side, and there's a snap-on cover that should let you look under there to see if the cowl is obstructed. You should also check for a plugged A/C drain, water in the HVAC can cover the evap and block off airflow.

 

[Telboy68]

Would that happen even if I had heater on and no AC? I haven't had a on for a while? I was thinking it may be a mode door actuator, I'm trying to find a schematic or diagram to see where I need to look. When the AC/heat is on I can hear air blowing loudly but I just don't seem to be getting any into the car and I can't change the modes.

 

[VStar650CL]

Would that happen even if I had heater on and no AC?

Yes, because the air always passes through the evap even when the heat is on, but is diverted away from the heater core when the A/C is on. So if the evap drowns, the airflow is cut off on all settings. The A/C will always run on any "defrost" setting, so winter doesn't mean the A/C won't run.

It depends on the mechanical design whether the evap can drown or not, in some HVAC's it's mounted too high for that to happen. I frankly don't recall the exact location on R52 Pathies, but it's worth checking.

 

[Telboy68]

Checked it and seems fine, I found the mode actuator, or what I think is the mode actuator up above the drivers feet and when I change modes I see that the actuator doesn't move. Not sure it's the actuator or what controls them are they direct to the controls or is there a module of some kind? If I was to disconnect the actuator could I use a meter to check? Does it send voltage or an electronic signal?

 

[VStar650CL]

On an R52 Pathfinder the servos are all connected to the HVAC Auto Amp by a shared LIN bus. The Amp sends out addresses and commands, and the servos assume the position they're told to. What puzzles me is that you have no airflow. The Mode servo can change where the air comes out, but it can't shut off the flow. Only a blockage can cause no air anyplace.

 

[Telboy68]

So if I turned the air off and the circulation then how does air not come out of the vents? This has totally baffled me. Thank you for all your assistance

 

[JohnPA2006]

2019 Nissan Pathfinder S no aftermarket mods. What happened is I am able to change the mode on the control panel, I hear the fan and it changes speed when I adjust but only a little bit of air comes from dashboard vents and when I change mode it does not change. No air at feet or defrost. I changed the cabin air filter and still the same. Can anyone help me with how I can troubleshoot, it is just out of warranty 6 months ago. Any help is appreciated.
Thanks

I have to ask the obvious questions. Please excuse them If they were already done. Sorry if any of my advise seems silly.
I have a 2015 Nissan Rogue SV , which is similar, sort of....
1. If a new cabin air filter was installed, did the plastic wrap get removed from filter before installing?
2. Make sure the tiny little door to access the cabin air filter is closed.
3. On the vents on dashboard, the tiny dial on the right of the directional fins, make sure the dial is "Open" as each vent can be closed
4. Look under your hood, check the air filter in engine bay, make sure you dont see any evidence of rodent nests
they like to make homes inside your air filter box, or on top of engine block (under the plastic beauty covers if present)
5. When you had the cabin air filter hatch open, try to shine flashlight in there to see if you any debris is there?
6. Here is a Youtube video on how to access and check and clean out your blower motor. Leaves, debris, mouse nests, anything can be in there.

Good luck