[wradar]

Have you checked that the blend door is functioning properly? If that's hung up, it'll never get cold.

How do I check that?

 

[Punisher69]

How do I check that?

You'll have to check it with either a very good scanner or take the HVAC apart. The actuators are known to break and more than one door has fallen completely off (which causes what you're experiencing).

Blend door actuator replacement

At least I'm pretty sure that's what's needed... passenger side doesn't change temp no matter what setting you're at. You can hear the motor spinning, but nothing changes. And when you first start it, for about the first 5 minutes, it makes the fan ramp up and down as it tries to change the...

www.dodgedurango.net

Should give you some help.

 

[wradar]

You'll have to check it with either a very good scanner or take the HVAC apart. The actuators are known to break and more than one door has fallen completely off (which causes what you're experiencing).

All vents blow hot when I set the heater to full HIGH (hot), and all vents switch from hot to ambient when I switch to full LOW (cool), so it seems the doors are working. Unless I'm misunderstanding what the doors do...

 

[Punisher69]

All vents blow hot when I set the heater to full HIGH (hot), and all vents switch from hot to ambient when I switch to full LOW (cool), so it seems the doors are working. Unless I'm misunderstanding what the doors do...

There is one door that switches from the heater core side to the a/c side. If it's stuck or the actuator is broken, it will blow a combo of both hot and cold. Might be a trip to the dealer.

It happens on the cars more often than it should.

What Is A Blend Door Actuator And How Do I Know If I Need A New One?

The blend door actuator is part of your car that you probably don't think about very often. It can easily get overlooked because most people hear "auto repair" and immediately think about their brakes or tires. However, the blend door actuator has a very important job, it helps control the...

wrench.com

 

[Duh-rango]

Got a DIY AC recharge kit and used the pressure gauge to check low pressure port, with engine running, AC on Max with recirculate engaged. Pressure indicated ~40 psi on the gauge (middle of the green zone).

Ambient temp about 62, and the vents in the front only got temps down to 67-77 (depending on which vent you checked). Rear vents only got down to 68.

So, weird noises, pressure seems ok, but AC isn’t blowing cold at all.

Compressor? Other ideas?

FYI there are a couple of TSBs regarding AC performance for 2014 durangos.

 

[Chase300]

Got a DIY AC recharge kit and used the pressure gauge to check low pressure port, with engine running, AC on Max with recirculate engaged. Pressure indicated ~40 psi on the gauge (middle of the green zone).

Ambient temp about 62, and the vents in the front only got temps down to 67-77 (depending on which vent you checked). Rear vents only got down to 68.

So, weird noises, pressure seems ok, but AC isn’t blowing cold at all.

Compressor? Other ideas?

Those are not accurate...you need a set of professional A/C gauges.
You're low on Freon...I know that sound.
Best is to fully discharge, hook up vacuum pump to check for leaks and then full recharge if vacuum test shows no leaks.
This should only cost around $100 at A/C shop...well at least here in GA.

Here's a good DYI guide;

 

[Duh-rango]

No way that is $100 here in IL. If they evacuate the system they generally put new refrigerant back in and with the cost of 1234yf is like 10x that of 134a so it's going to be a much higher service charge.

 

[Chase300]

Oh good point Duh-rango...I was going on R134A price not 1234YF which is like $100+ per lb. at a shop.
So more like $500 for 1234YF freon...as you need a special machine to evacuate it.
DYI is under $50/lb.
Durango takes 2 small cans to recharge.