scatterbrain

I have an issue where when the AC is on, the driver side air isn't as cold as the passenger side. As I'm not really a DIY-type of person (unless it's REAL easy like replacing a dome light or something), what would I expect to pay at the dealer for diagnosing and/or fixing the problem (which I suspect may involve AC refrigerant recharge. My car is a 2013 Acura RDX.

RDX-Rick

The part of the AC system that gets cold is the AC evaporator which is located in the area behind the glove box. The blower fan is located adjacent to the evaporator and blows air past the evaporator and into the ducts under the dash that direct it to the different locations based on your selection (windshield, face, feet, etc.)

So if the 2 sides are different temperatures, it can't be the result of the AC system, it is more likely to be a problem in the ducting, or the damper doors that open and close to redirect air to the different locations.

Since the drivers side is further from the blower it is normal for there to be less air pressure on that side, but the temperature should be the same. I feel that you may be making your claim of temperature difference based only on holding your hand in the air stream. I bet if you actually use a thermometer you will find there is no difference.. I suggest getting a thermometer like this image and checking both sides more accurately. If you can confirm there is a difference (and how many degrees) we might be able to offer some other tests to perform.

I purchased this exact thermometer ($9.97 CDN at Walmart) to test the efficiency of my own AC system. On a hot day, select the lowest temperature on the thermostat, turn on the blower at maximum speed, make sure that "recirc" is NOT on. The temperature coming from the face vents should be at least 20 degrees Celsius cooler than the outdoor temperature (depending on humidity). The temperature will never drop lower than 4-7'C to prevent freezing, so the test needs to be done on a day over 27'C.

You should also perform your driver to passenger comparison at full blower speeds.

EDIT: You do have the dual AC system set on "Sync" mode don't you?

scatterbrain

Thanks for your input. Yes, I do have it on "sync" so the thermostat is set the same on both sides. I think there really is a temperature difference between the two sides... and it's not only me that's physically compared the two sides. The difference is definitely noticeable particularly on really hot days when the driver side almost feels like the heater's on and the passenger side feels real cold. But I do like the idea of using the thermometer to test. so I'll do that. After all, I've been in need of a new food thermometer for cooking meats anyways.

So if it ends up being an issue with ducting and/or damper doors, is that an expensive procedure to fix?

RDX-Rick

I would start testing the diverter doors by trying to direct air to every possible combination of outlets. For example, defrost, face vents, floor vents, and whatever other combinations are available on your 2013 model.

Also verify if the air velocity/pressure from the driver side and passenger side are roughly equal for each setting (remember the drive side will be somewhat less due to the length of the ducts). If you find that the air flow is greatly reduced in one setting, verify that the air is not coming from a different location. For example if the flow is reduced from the face vents, check if it is coming from the floor vents instead.

If you confirm all the damper doors and airflow is good , then you are either looking at a possibly defective AC CPU that can't control the drivers side temperature blending door, or the blending door is not working properly. That could be something as simple as a vacuum hose that may be pulled off.

Have you tested with the dial set to the very lowest setting? That may trigger the CPU to switch to maximum cooling and ignore the thermostat.

Have you tested if the passenger side will output heat or is it stuck in maximum cooling all the time?

Most of the modern AC systems have a built in diagnostic system which is accessed by pressing a combination of buttons. I did a quick Google search for "Acura AC Self Diagnostics" and found several results. Since I don't have a 2013 model, I don't know if your system has the buttons decribed in those procedures. (You could also search for Honda AC Self Diagnostics for more results).

scatterbrain

Good suggestion on trying all my modes and testing heat. I'll try that next when I get a few cycles. However, it might he a little tough to determine if heat is working with this nasty heatwave we've been having lately.

And maybe I'm imagining things, but I also noticed that the driver side seems to blow cooler when it's cooler in general (i.e. car is in a shaded area). I know it seems pretty obvious that it'll do this, but what I mean is that the air is clearly colder than the outdoor temp (it's been 100 degrees lately... in the shade)... as though AC is actually doing its job.

And I did manage to run the AC diagnostics. It's pretty neat... sort of cycles though all the modes for a few seconds. In the end, the code came up displaying "no". I'm not sure if that means "no problem" or if it's actually a problem code. I'm still searching around google for result code list, but I haven't found one for my model yet.

markAZ

Do you have navigation in your RDX? If so, the climate control system can adjust the temps on each side which might account for the difference you're seeing.

From the owner's manual (for the 2014 RDX, I don't know if 2013 is any different):

'In AUTO mode, the system adjusts each temperature
based on the information of the sunlight sensor and
the sun position updated by the navigation system's
GPS.'