Why does my car AC vent blow hot air when driving even when the AC is off?
Depending on system design, you either(A) have a heater control valve stuck in the open position, thereby causing heat to flow through the system at all times.The fact that you can't terminate air flow at the vents, however, would not really fit that scenario, without something otherwise unrelated failing at exactly the same time.If the blower motor runs even with the switch off, then that circuit is shorted. But that's rather unlikely, and it doesn't account for the hot air (just like the hot air doesn't explain the undesired flow) .It's more plausible that (b) your car relies on a vacuum signal to control the various doors partitioning airflow through the HVAC box (some mfrs, like Ford, use vacuum-operated actuators in lieu of electronically controlled motors and solenoids). If the system described doesn't use a heater control valve (some don't) and that vacuum signal was somehow interrupted or lost, then your blend door would default under a spring load to the heat position, and your recirculation door would default to fresh air. The ram air flow from vehicle speed would cause hot air to flow in the passenger compartment at all times, Even with the blower motor commanded OFF.On the system described, one open, damaged or disconnected vacuum line coupling (usually located at the main HVAC supply line at the firewall) would cause the complaint described. Its also possible that a vacuum check valve has failed, or a vacuum reservoir is leaking, in which case the problem would disappear with the engine idling, but occur at engine speeds above 1500 rpms.
Air only blows through defrost vents not front vents in my car?
the air blend doors are operated by a vacuum supplied by the engine, somewhere between the vacuum source on the engine and the firewall where a hose goes into the car passenger area, there will be a plastic reservoir that holds reserve vacuum, you more than likely have a leak in the system have fun, use some common sense and logic and you'll locate it, in a quiet area with the motor idling safely in park with wheels blocked you might be able to hear it hissing, don't get fooled the hiss may sound like one area and the leak across the car, get a car repair manual from a parts store for locating it there is only about 30 feet of vacuum hose on the average a/c system learn to love it the engines are too hot to work on in summer stick with h/vac
What does it mean if my cars AC only blows cold when pressing the gas pedal, and blows warm when idling?
I’ll second a lot of the prior answers and add a bit.Vacuum leaks can drive you nuts. Could be easy to get to in the engine compartment or hidden way up in the dash. If it’s in the doors up under the dash you’ll usually notice a change in the airflow inside the car.Freon leaks away gradually because it’s a tiny molecule.If you need refrigerant added I would suggest you invest in also changing something called the filter dryer bottle.Freon + moisture = acid in the system and that’s obviously always major trouble. The moisture actually gets through things like the hoses on a molecular level no matter what. That’s why that bottle should be changed every 3–4 years , mostly to get some fresh desiccant in there to get any moisture.After changing the bottle the system has to be pumped down with a vacuum pump for a while to evaporate any other moisture then recharged.This is an odd one but the current 134a freon will drop off in performance if the system is overcharged with too much freon. You don’t often see this. There is a chart of suggested hi and low freon pressures as per outside temp that most don’t bother to use when charging a system.A lot of systems have pressure cut outs for low AC pressure and other things, as already mentioned. Watch the belt clutch on the AC compressor and see if it cuts out at idle. That would usually indicate one of the switches kicking the compressor out for some reason.The heat the AC pulls out of the car gets dumped to the atmosphere by the condenser coils in front of the radiator. This happens much more effectively if you’re moving and air is flowing over the condenser. Ever notice it gets cooler in the rain? Water cools the condenser even better.Possibly combined with…I live in Florida and some auto AC systems just aren’t designed to move enough BTUs to counter the solar gain plus high outside temp through the glass in a hot climate.
My car has the passenger side blowing hot air and the drivers side blowing colder air. Why? There are two controls for each side.
If the vehicle has a dual zone A/C, then the most common problem is a bad temperature door actuator. This actuator is what controls the temperature door. If the door doesn’t open, the cool air won’t get in. Dual zone A/C systems have a temperature door for both sides.Vehicles without a dual zone A/C system usually experiences this problem if there is a low Freon charge in the system. This is commonly missed by mechanics because the Freon gauge will read normal even if it is low on Freon. For instance, a system that is ½ lb. low will cause the passenger side vents to blow cooler air, and the driver’s side to blow warmer air. In this case, there is simply not enough Freon to cool the driver’s side. Make sure you have your Freon levels checked and filled if needed.
If my car air conditioner is not consistently blowing cold air, what is the problem?
Hex Auto Parts Common AC Compressor ProblemsCool But Not ColdIf the air conditioning is set to max cool and fans on high, but is only blowing moderately cool air:1. Check to see that the cooling fans on the condenser or radiator are running when the air conditioning is on.2. Look for any restrictions like leaves, bugs or dirt that would keep air from passing over the condenser.3. Check the cabin air filter to ensure that it is not clogged.4.Check the pressures in the system using a manifold gauge set.Compressor and ClutchThe AC compressor clutch is one of the most common points of failure on the compressor.The compressor is the work horse of the air conditioning system, powered by a drive belt connected to the crankshaft of the engine. When the air conditioning system is turned on, the compressor pumps refrigerant vapour under high pressure to the condenser.1. With the engine running turn the A/C on max cool, set fans high, and make sure that the clutch is engaging on the compressor.Note: this is not the pulley, but the center piece that engages the pulley to the compressor shaft.If the clutch is engaging and disengaging rapidly, the refrigerant may be low.2. If the clutch is not engaging, use a voltmeter to check for voltage getting to the compressor.3. If there is voltage - the clutch may be bad.If there is no voltage - a cycling switch may be bad, a fuse may be blown and the system may not have enough refrigerant pressure to trip the low pressure cutoff switch that cycles the compressor.How do you test for an A/C system leak?One of the most common AC temperature problems is low refrigerant. The AC system is closed, so refrigerant should not be lost unless there is a leakDetecting leaks:Black light enabled dyes. You read that right. A lot of refrigerants are pre-mixed with a special U.V.dye that shows up under black light. We’ll run a black light over your A/C system to see if any dye shows up.Bring in the sniffer; A sniffer is a special device that hones in on the refrigerant’s chemical components. If there’s a leak, our sniffer will sniff it out. A damaged ignition coil could even cause an electrical short that can damage your Honda Civic's electrical system or blow a fuse.
How can I install rear air vents in my small SUV?
I have a 2005 Chevy Equinox which doesn't have rear A/C. It drives my family nuts because living in Florida it gets HOT! In the rear it has floor A/C, but that doesn't really help them because it just blows on their feet. What I want to do is cap the floor vents and redirect them to the ceiling. I want to get the round ceiling vents like for a ford expedition or a GMC Yukon. My only concern is how I can get the air to the ceiling. Is there a pipe or something that could carry the air well while still bending for the curves? Even if it's ugly, I can hide it. I know it's kind of strange to add air vents to my car, but hey, I've done stranger things lol. Any help would be great! Thanks so much!