Cabin Climate Help

icetab · Post by **icetab** » 05 Jun 2016, 16:23

Hello all,

I purchased a used 03 V70 2.4T this past winter. With the heat on (any setting, any speed), after about an hour of driving, there is no air movement from the vents. I can hear the fan blowing and feel some faint heat from the vents when this happens. As the car has 110K miles I thought the problem might be the resistor or the blower motor. A few weeks ago, I replace both as the same situation started occurring with the AC. I just took the car on a 1,200 mile trip and found the issue to still be present. If I shut the fan off for around 30 mins, wait, then turn the fan back on I can get another hour or so of air. Unfortunately, I had to keep repeating this process the entire trip. Called the dealer, they want close to $200 just to look at it for an hour. However, the tech on the phone told me he thought the car might have a bad actuator motor. Either way, I thought I would reach out before letting them pull the dash out (dealer said this). If anyone could tell me where to find the motor or has a link to what part they think might be the issue, please let me know.

Other details: Currently, I run the climate control 64 degrees, "main", and on the middle vent setting. I have tried other temp settings and the same issue occurs. I have tried other vent settings, and the issue persists after the hour time mark.

Post by **oragex** » 06 Jun 2016, 05:18

It is not uncommon for the vent flaps to go bad inside the dash. But first, get a vacuum cleaner and place it near the small that sits above the right temperature knob, there is the cabin temp sensor in there and can get covered with dust. Alternately, this same sensor might go bad but I rather think it's won't work at all when this happens. Careful as the sensor is fragile, better not insert anything through the grid.

Side note, removing the dash might be awful expensive at the dealer, a local independent Volvo specialist if available can help cut down the costs.

icetab · Post by **icetab** » 07 Jun 2016, 16:57

Thank you for the reply. I vacuumed out the sensor as suggested. There are visible trails of some sort of junk in there that just won't come out but I'm going to try it as is. So far I haven't driven anywhere over an hour yet.

Post by **oragex** » 07 Jun 2016, 17:03

It's the tip that shows behind the grid that is important, as long as it looks clean it should be fine. With care, it can be wiped with a wet q-tip but usually it gets covered with dust, unless prev. owner spilled some coffee/drink over it

icetab · Post by **icetab** » 20 Jun 2016, 08:25

Update: Finally went on a 2hr + trip this weekend. The AC quit working again -- in terms of cold air not coming full force out of the vents. I had my fingers crossed that vacuuming the sensor worked. One thing I did notice this time is that, while I could feel the cold air at the vents (again, not blowing), there was a large amount of warm air coming out around the left side of the glove compartment box. I could feel this warmer air pretty good.

Does anyone know if there is some sort of central actuator door directly behind the dash/glove compartment area? As in, one that would sit directly after the blower fan, sort of on top of it?

Any ideas? If I pull the entire dash out, how many components I'm looking at to replace to narrow down this AC problem? Wife says if I can't fix it, the car has to go, and I personally love the thing.

Post by **chrism** » 20 Jun 2016, 15:23

When the problem arises in "heat" mode, is it possible that you were running the defroster also? The reason I ask - it sounds like your car is doing exactly what mine did when the evaporator was freezing up. In my case, replacing the evaporator temp sensor was the fix. Even though the evaporator was getting good and cold, the compressor wasn't cycling off to allow it to melt off the ice. When running the AC, you should be able to hear the compressor cycle on-off-on-off.

Try this - When driving around with the AC on and the vents begin to not blow, click the AC button OFF (which turns off the compressor) but let the blower continue to run. If, after a minute or two, the vents begin to flow warm or kinda cool air again, click the AC button back ON and see if it blows cold again until the vents start to shut down again. Does this cycle repeat?

https://www.matthewsvolvosite.com/forums ... tor+sensor

icetab · Post by **icetab** » 20 Jun 2016, 20:14

Chrism. Thank you for the reply. I have tried what you're suggesting and there is no change. I can feel a faint air movement behind the vents (with the fan set on high), but it's not pushing through. The only trick that seems to work is to shut the entire system down for 15 - 20 mins, then I'll gain about 1/2 hour of proper air movement.

Again, I'm currently running this on the middle vent setting and I believe it would act this way no matter which vent setting is selected. Do you think I should go ahead and replace the evaporator temp sensor anyway?

I'm considering bringing down to the dealer, but the closest dealership is 2 1/2hrs from my location. I'm also afraid they'll try to screw me. Last time they wanted a couple grand to change out the front struts.

Post by **chrism** » 21 Jun 2016, 21:44

Evaporate temp sensors are about $35 and it takes 15 minutes to R/R.

But let me ask, when you first turn it on and let's say you have the blower about half speed, how long before the compressor starts to cycle on-off. Does it EVER start cycling or does it just run and run until the airflow shuts down? If that's the case, then yes, I think I'd replace the evaporate sensor. If you do replace it make note of which direction the sensor is clocked as there is a certain way the air is supposed to flow across it.

Oh I forgot- you can measure the resistance across the sensor contacts at various temperatures all the way down to freezing with the help of your kitchen freezer. I think the link I posted earlier in the thread describes the proper temp vs ohms.

VNDETTA · Post by **VNDETTA** » 12 Jul 2016, 00:38

This is going to sound incredibly stupid, but I've seen it happen with my own two eyes.

Find the cabin air filter. Remove it completely. Is it filthy? Do you have a large buildup of debris where the filter goes? I had a friend with a TDI Jetta, about a 2005 model I think, that had this exact problem. I reached under the dash, yanked out the filter and "poof" all the air came back.