[KlonedAspect]

Hello all,

I am new to Mazdas, picking up a 2016 3 i Touring Hatch last friday. So far I have really enjoyed it.

I am having an issue with the the heater fan always blowing at a constant speed no matter the setting and if I turn it off it still blows constant and shows the setting its blowing on the climate screen (everything else is dark on the screen). It has the dual climate control. I have searched this forum and have not been able to find a thread with a similar issue.

I am wondering if the Heater blower resistor has gone bad? Does anyone have a pin out/schematic for the resister so I can test it with known good resistance values and continuity between pins? YouTube and other google searches have not been successful for the 2016 range of models.

I have found the part numbers on rockauto. This is my first post so I am unable to post links to them. I can only find one resistor on Ebay.

They seem to be pricey so I don't want to shotgun a part at it. Does anyone have any alternate ideas, sources for parts or any information that could be worthwhile? I do not have a local Mazda dealership and of course I rolled over 36k miles on my first commute to work.

Thank you.

 

[gregersonke]

I would still take it to mazda, BTW, 2014-2017 are basically the same and the mazda6 cx5 use similar items. If the resistor blew, then something caused it to blow. Hence the reason I say dealer is the way to go because if the resistor isn't the only problem then they'll have to cover replacing it again if they didn't fix it the first time. Thus the reason I think something likely caused your resistor to blow. Try pulling it out and take a look and see if there is anything obvious going on. If it's staying on even when you turn it off that tells me something caused a full grown across the resistor and the problem should be visual.

 

[3withthreepedals]

Take it in anyway and see if they'll goodwill it for you since you're so close to the 36k figure. Make sure to emphasize it started before it turned over.

 

[KlonedAspect]

I will see if I can find and call a dealer close enough to take it in. I'll remove it and see what I can see as well. I'll let you know what I find out. Thanks!

 

[Lanny]

When you say you turned the fan off, did you tap the OFF button to disable the auto climate control completely? Otherwise, the fan will still run (and the air conditioner will run as well unless you tap the AC button). Mazda climate control generally works well, but on "auto" it does what it wants with no flexibility.

 

[2017mazda3]

When you say you turned the fan off, did you tap the OFF button to disable the auto climate control completely? Otherwise, the fan will still run (and the air conditioner will run as well unless you tap the AC button). Mazda climate control generally works well, but on "auto" it does what it wants with no flexibility.

Absent an actual electrical issue, I think you're onto something because it's really not clear how you have to completely shut off the system by tapping the middle control button a couple of times and if you subsequently hit any of the other buttons on the climate control you actually turn the system back on when you might not want to. It took me a bit of time to figure out as well. The climate control in today's cars are much more sophisticated than older cars. Yet there really is no real solution to clear off foggy windows on cold rainy days except to blow cold air.

 

[KlonedAspect]

When you say you turned the fan off, did you tap the OFF button to disable the auto climate control completely? Otherwise, the fan will still run (and the air conditioner will run as well unless you tap the AC button). Mazda climate control generally works well, but on "auto" it does what it wants with no flexibility.

Yes, when I tap the off button to turn the system off completely. No lights are on in the temp dials. Only thing that stays on is the the arrows pointing to where the fan is blowing. I will see what pressing off multiple times does. I will see if I can upload a picture.

Contacted the closest dealer to me. They are unwilling to look at it under warrenty. Oh well. I will dig into and see what I can find out.

Thank you all for the tips and info.

 

[KlonedAspect]

Pressing off multiple times made no change. I had my fingers crossed.

 

[KlonedAspect]

I removed the fan controller and let it hang while I turned the heater on. Immediate burnt electrical odor coming from it. I am worried about something else being wrong in the system but on the same hand this controller isn't just a resistor. There is a full pcb with all sorts of goodies in it. I'm going to replace it and see what happens. Once again thank you all.

Also here are a couple photos. One with the system on and one with it turned "off"

 

[gregersonke]

Don't contact the dealer, contact mazdausa on their website. They'll tell you if you get goodwill or not. Dealers don't like warranty items if they can help it.

 

[3withthreepedals]

I misread what you wrote originally but it is normal to have it show the air direction even with the system off. I thought you said the fan speed display was still on even after pressing 'OFF'. I've had cars that worked both ways. My 2004 Santa Fe (manual climate) had an "OFF" setting on the air distribution knob but even in that off position, a small amount of air would still come in through the windshield vents at speed. My 2012 Elantra (also manual controls) was turned off via the blower knob but air from the outside would come in to wherever the blend settings were set and the corresponding light would be on.

 

[Nathan Carter]

Yet there really is no real solution to clear off foggy windows on cold rainy days except to blow cold air.

You'll get best results by running both the heat and the A/C at the same time.

The A/C (evaporator coil) will remove excess moisture from the air when it cools, then the heat will warm it back up so the air coming out of the vents is warm and dry, ready to absorb what's on the glass.

Turn off recirculation, because the cold wet air from outside is less moisture-saturated than the warm wet air in your footwells.

 

[2017mazda3]

You'll get best results by running both the heat and the A/C at the same time.

The A/C (evaporator coil) will remove excess moisture from the air when it cools, then the heat will warm it back up so the air coming out of the vents is warm and dry, ready to absorb what's on the glass.

Turn off recirculation, because the cold wet air from outside is less moisture-saturated than the warm wet air in your footwells.

I know that is the way the system is suppose to work and it does if you give it enough time and/or the fog doesn't build up too quickly do to the blow hard passengers. I believe I have even read several places where Mazda suggests running the AC all the time to mitigate these problems...problem is the cold air solution on a window still works usually faster when the fog builds up quicker than the system can handle, as the physics of the whole thing requires the exterior and interior glass to be aprox. the same temp to clear the fog.

 

[2017mazda3]

I removed the fan controller and let it hang while I turned the heater on. Immediate burnt electrical odor coming from it. I am worried about something else being wrong in the system but on the same hand this controller isn't just a resistor. There is a full pcb with all sorts of goodies in it. I'm going to replace it and see what happens. Once again thank you all.

Also here are a couple photos. One with the system on and one with it turned "off"

It doesn't address your problem but just realized the climate control was another one of those small interior tweaks they made on the 2017 model from the 2014-2016 models. The "mode" button doesn't exist on the 2017 and was replaced with another directional button. However, what I don't get was Mazda's reasoning and redundancy with these 2 buttons. On the 2017 both buttons actually do the exact same thing if you press them 3 times as they just recycle thru the exact same 3 air directions, even though the symbol on the buttons show different directions.

 

[Nathan Carter]

blow hard passengers

maybe that's why mine works so well :laugh2:

After coming from a 16-year-old car with, uh, "intermittent" A/C functionality, the Mazda3 seems to de-fog practically immediately.

 

[DougRz]

the physics of the whole thing requires the exterior and interior glass to be aprox. the same temp to clear the fog.

I don't think this is correct. Since the glass is already same temp inside and out, the warm, moist air inside hits that cool inner surface and condenses on it. Warming that inner surface to the same or higher temp than inside is the physics behind stopping condensation.

That said, blowing cold air might work faster since you, 1, don't have to wait for engine heat and, 2, might sufficiently displace warm, moist air in contact with the inner surface.

 

[2017mazda3]

I don't think this is correct. Since the glass is already same temp inside and out, the warm, moist air inside hits that cool inner surface and condenses on it. Warming that inner surface to the same or higher temp than inside is the physics behind stopping condensation.

That said, blowing cold air might work faster since you, 1, don't have to wait for engine heat and, 2, might sufficiently displace warm, moist air in contact with the inner surface.

In a perfect scenario your solution is most perfect...Not in my scenario as it specifically pertains to auto glass, and condensation building up quickly while driving...the outside air is colder and generally dryer (winter months) than the inside. The inside condensation being caused by breath and body heat from passengers as that is the specific reason for the interior condensation/moisture in contrast to the cold exterior glass, which obviously builds up and occurs "subsequently" to entering the car, not immediately...Unfortunately, there is no comfortable/immediate solution in the summer/humid months with higher dew points either when you have to blow hot air on the inside of the glass to help clear outside condensation/fog (along with your wipers) when the outside of the windshield is warmer than the cool A/C inside.

Grant you, it is actually why it is suggested you run the AC/Climate control all the time during cold months to remove the condensation from inside the car while running the heater at the same time, but in situations where the build up occurs quickly, and likely with more passengers, cold air and opening the windows works quicker to remove the moisture.

Also, make sure the recirculate is off as you are trying to remove the moisture from the interior cabin in all cases.

 

[KlonedAspect]

Its been a bit but I have an update. I ordered a new heater control module and the issue is fixed. It took a long time for the module to arrive after ordering. They seem to be pretty hard to source. I ordered from Mazdaswag.com. Best price just had to wait for them to get the part from their warehouse. After that they shipped fast. Happy with their service for sure.

The fan now shuts off when the system is turned off and I am able to control the fan speed. As 3withthreepedals stated the image of where the fan is blowing stays on when the system is shut off.

Still watching for anything that could have caused the module to fail besides a faulty module.

Thanks all for the info and support.