weather is getting hot here and just notice the dashboard vent is blowing warm air (AC off) even the temp set to the coolest. when switch to defroster/window vent and the air is way cooler. switch back from defroster back to dashboard it blows cool air for a minute then the air gets warm again. any idea what's the problem?
Dashboard Vent blowing warm air?
- Thread starter WHY
- Start date
mazdadude
ZOOOOOOOOOM ZOOOOOOOOOM
- :
- '16.5 Mazda CX-5 Touring
When you turn dial to defrost mode, your AC is then turned on, even though your AC switch is set to the off position.
This is normal operation, and discussed in your owners manual.
If the AC did not come on during DEFROST mode, your front window would fog up and cause a hazard.
This is normal operation, and discussed in your owners manual.
If the AC did not come on during DEFROST mode, your front window would fog up and cause a hazard.
Last edited:
- :
- 2008 Mazda5 GT
This irks the crap out of me too.... (mad)
My question is, would luxury cars also have this 'feature'...
Looks like that's the case. that also explained why sometime the car would leak "condense" water when i shut the car even I never turn on the AC. but again the vent air it blow from dashboard is super warm. make it kinda hard to drive with out turning on AC.
mazdadude
ZOOOOOOOOOM ZOOOOOOOOOM
- :
- '16.5 Mazda CX-5 Touring
I agree. But I am wondering if the air coming out is actually "warm", or just warm compared to feeling it against the "DEFROST" mode? It is possible for the cold/warm air mix door to not be fully functioning.
I also see by your sig that you have a GT, and that has the AUTO CLIMATE CONTROL system, so I am unsure if there is a way to do what you want? AC OFF, VENT TO FACE, MAX COLD, FRESH AIR?
Last edited:
- :
- 2006 Mazda5 Touring
What I have done since day one on hot days to aleviate the problem is: Turn on the AC, set to 60 degrees set temp, turn on fan to middle speed, air direction face only. Let the AC do its thing for about three or so minutes, basically until the air coming from the vents is frosty cold. Turn off AC, leave set temp at 60 degrees, air direction at face only. The dashboard on these cars is such a huge expanse of black, heat-soaking plastic that the dash vents get hopelessly heat-soaked sitting in the sun. I have found that by running the AC long enough to "cool" the plastic that the air passes through I can drastically reduce the effect you are describing. Try it out one day, I think you will find this technique works quite well on all but the hottest of days. HTH
Cars with auto A/C only run without the condenser in the mode blowing to face and feet at the same time. I put ours in that mode and just turn the fan up, but it always stays hot down around my feet and legs, while also blowing out hot. One of my chief complaints on this car.
Wishmaster
Member
- :
- 07 Galaxy Gray AT Mazda5 GT
Also doesn't use the condenser in face only. (In an '07 GT)
- :
- 2008 Mazda5 GT
Tried that, works for a very short while. I don’t buy the dashboard getting hot b/c it does it on cool days with no sun. “Something” is warming the air up. One of my leading suspicions is heat soak coming from the engine bay - poor firewall insulation and the cowl is pretty poor. The radiant heat could be getting into the HVAC plumbing/dashboard.
- :
- 2006 Mazda5 Touring
That and the radio, which in the case of mine gets right toasty.
- :
- 2008 Mazda5 GT
I was SHOCK when I first observed how hot the glove box gets! It is like an oven in there.
Here’s a simple test. Park car under shade with windows open (no sun exposure) to ensure air temp is equalize. Turn on just the fan for 5-10 mins and see air flow gets hot. This would eliminate sun/engine/radio. Next would be to introduce one item at a time and see where it goes from there. Someone what to do it and repot back?
Here’s a simple test. Park car under shade with windows open (no sun exposure) to ensure air temp is equalize. Turn on just the fan for 5-10 mins and see air flow gets hot. This would eliminate sun/engine/radio. Next would be to introduce one item at a time and see where it goes from there. Someone what to do it and repot back?
- :
- 2006 Mazda5 Touring
My experience has been with the fan OFF, just allowing outside air to flow through. I will usually crack the sunroof (tilt) to facilitate circulation. On hot days I do the "run AC to cool vents" thing and I haven't ever had a real problem with the air getting warmer afterwards. I do agree that running just the fan will make you more aware of the rising air temp though, I tried it on the way home last night and you can FEEL it getting warmer. I don't think insulation was one of Mazdas prime engineering goals on these things, my center console gets warm enough to dehydrate fruit on my drive home every day, makes keeping a soda cold a real problem 
Not on our '09 GT. Cycles off and on in every mode other than mixed, even with the A/C button turned off. I wouldn't have noticed had a member here not said something about it years ago.
I try to be nice these days, but I hate the A/C on these cars. Works great, but is just a stupid interface and senseless functionality at times.
Got a Lexus IS350 and it does have this feature. I believe it is, as someone else on this thread already mentioned, a safety feature to avoid fogging up of the front windshield during less warmer outside temps. Also, based on my observation, on hot days, it does help cool the interior a lot faster when air is set to defrost (windshield) and floor vents than directly in your face as, I believe, most of the heat is coming from the windshield where there is less to no insulation.
Last edited:
Word of advice from someone that experienced it in the past (not with a Mazda5). I wouldn't set the dial to defrost mode in a hot day. The cool blast from the A/C could shock the windshield and instantly crack it.
- :
- 2008 Mazda5 GT
Thanks for confirming but that's not the 'feature' in question
But you could confirm when driving the IS350 with just the fan on (set to lowest air temp), does air get hot?
Last edited:
Thanks for confirming but that's not the 'feature' in question
But you could confirm when driving the IS350 with just the fan on (set to lowest air temp), does air get hot?
Air does not get hot.
Hasn't been an issue with mine.. Could it have been an aftermarket windshield on yours? I've heard of rear windows cracking when rear defrost is turned on, but not the front windshield..
