Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [hvac]

HVAC - Heating, Ventilation, Air Conditioning.

Includes the air ducts, controls, blower motor(s), blend air doors, vacuum and electric controls, heater core, AC evaporator.

196 questions
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When car is standing still, I smell Diesel exhaust. Why?

In my 2003 Opel Vectra, the cabin air smells of Diesel exhaust while stopped at e.g. a red light. The exhaust smell goes away when driving, and it also doesn't come back if I turn the ventilation off before stopping at a light. It's not…
Torben Gundtofte-Bruun
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Is it okay or useful to run heat and AC at the same time?

Most cars that I've seen in my life have a heat slider or dial, which goes from coldest to hottest, and also a button or switch that is labelled "AC". When the heat dial is set to cold, turning on the AC switch makes it even colder. I was under the…
snetch
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Can a car AC unit be run on just the car battery?

This might be a silly question but I was wondering if a car AC unit be run off entirely on battery or alternator? As this could help in Preventing power loss during important times such as overtaking and climbing on slopes. Increasing fuel…
saurabh64
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how can I quiet a 'chirping' ventilation fan motor blade?

I have a 2006 VW Golf and the internal fan motor that blows the a/c & heat will start to 'chirp' (sound something like a bird singing) randomly. I believe the fan blade needs to be lubricated, but I have no clue how to go about accessing the…
Patrick
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3 answers

Are A/C Control Panels Universal?

Are A/C Control Panels (the panel that controls the: Fan Speed, Temperature, and Head/Foot air flow direction) in cars are universal, similar to USB connections are for computers? For example, I would like to to take the the A/C Control Panel out of…
Munstr
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My vents randomly switch between face / windshield... how do I fix this?

I have a 1998 Ford Windstar (more details on demand if necessary.) I rarely use any vent setting besides "face", and I try to avoid using AC because my gas mileage is already lousy. About two months ago, my vent / fan started blowing on the…
MT_Head
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Vehicle AC works initially, but after driving for a while (hour+), the airflow drops to the point being ineffective

I have a 2004 Ford Excursion with the 6.0 powerstroke. Most the time, the AC works fine, but after a long drive in hot weather, the front AC barely blows out of the vents. The rear works fine, in fact, my wife and I try to point those towards us,…
Alex Estrada
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What can I do to prevent my air conditioner from smelling moldy as the temperatures begin to rise?

What can I do to prevent my air conditioner from smelling moldy as the temperatures begin to rise? Every year someone I know or myself begins to get an odor from their air conditioner that's musty or moldy when the weather begins to get warm. I've…
DucatiKiller
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My AC works well at night only

I'm unhappy with the performance of my '04 Pontiac GTO's AC. Here are the symptoms: Cooling goes down to zero when the car is stationary, starts to cool after the car has been moving for some time It doesn't cool enough during the day (~ 35-45 °C…
Zaid
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How to get items out of the HVAC system from a 2003-2007 Honda Accord

Before I ruin my dashboard/car, I wanted to know if my approach is correct. I don't know much about cars but logically, it seems like a simple enough task to remove vents, reach in and grab items, replace vents. Some items fell down the center air…
Classified
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What's the quickest way to defog a windshield?

For a properly functioning auto, what's the quickest way to defog the windshield? There are lots of air control options - hot vs. cold air, exterior vs. recirculated air - but which are the most effective (assuming the auto is functioning…
KatieK
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Measuring A/C refrigerant I got 96 PSI, is 96 PSI bad?

I bought a car refrigerant gauge online because my A/C is not cooling the air at all and the first suggestion was to check your refrigerant to see if it is empty or low. I found out where my car's "low side" opening is for a 2008 Mazda 3. I started…
syn1kk
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Vauxhall Vectra C Blower Motor Sqealing / Clunking

I have just replaced my Blower Motor Resistor as my fan wouldn't work on any setting other than 4 (in line with a previous post: How to troubleshoot a fan that won't work unless it's on it's on the highest setting?). When on 4 I noticed a slight…
webnoob
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Why might lower settings of a dashboard fan not work if the highest does?

My wife bought a Nissan Note second hand and the internal ventilation fan works on the highest setting (3 or 4) but not on the lower settings. We've checked the fuses and all seems fine there. Could it be a problem with the switches inside/behind…
Bernhard Hofmann
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Water dripping on driver's foot. How to fix it?

Just this morning I noticed there is a water dripping into my shoes while driving. My aircon is open. The weather is sunny and warm. My car is Toyota Vios.
H3n
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