Why is my ac blowing hot air in car
AC is On, But It's Still HOT! Diagnosing Air Conditioning in Your Car or Truck!
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Is your AC not working like mine?
Well, in this video we're going to go over some of the components that you need to check
out.
Your air conditioning system is a sealed system with refrigerant in it and, for the most part,
you need a special tool to work on it, such as a recovery, recycle, recharge machine.
But there's some preliminary checks that you can do that could fix your AC that you don't
need special tools for.
Let's start from the front of the vehicle and work our way back.
In the front, behind the grille on most vehicles, you're gonna have your condenser.
It almost looks like a radiator, and most of the time it's right in front of the radiator.
And you need these cooling fans to be nice and clean.
You don't wanna see any debris on here.
If you see leaves in front of it, it's not gonna get some good airflow and that's gonna
cause the system to not work properly.
How the condenser actually works is compressed refrigerant comes into the condenser, the
air cools it off, and then the cooler refrigerant leaves the condenser.
So if you see anything in front of it such as leaves, or debris, or mud, or dirt, or
anything, you're gonna need to clean that off.
You can even take a garden hose and just clean it all off.
Sticking with the fact that we need airflow going through the condenser, you need to make
sure your cooling fans are working.
If they're not working at full capacity or they're only partially working, it's not gonna
cool the condenser down enough.
Either your AC is not gonna work at all or it's just not going to be working well.
Some of the reasons why your fans may not be working is you may have motors that are
faulty, you may have a bad relay, or a blown fuse, or even some other electrical issue.
On most vehicles, the second you turn that AC button on, both fans should come on and
should be on almost full capacity.
Now let's talk about the AC compressor which, on this vehicle, it's underneath.
You can see it right here, and it's driven by a belt, and it's what's gonna pump the
refrigerant through the system.
The belt is gonna spin the pulley, and when the clutch is engaged, it engages the compressor
and that's what's gonna compress the refrigerant and push it through the system.
Now if the belt fell off, like this one, then the compressor is not gonna be able to do
its job.
So that could actually be one of your problems, where you have to either replace the belt.
A lot of times if there's a idler or a tensioner pulley, sometimes those will seize up and
they have to be replaced, and that's what's gonna cause the belt to pop off.
If the belt that goes around the compressor pulley is okay and it seems normal, and you're
activating the AC and you notice that the compressor clutch is kicking on and off rapidly,
normally, that's an indication that the refrigerant level is low.
In the event that the refrigerant level is low, it's because there's a leak in the system
and you're gonna need to bring it to a professional to use that special machine that we talked
about earlier.
On this vehicle, you can see the AC compressor pretty good right here, and this is what makes
up most of the AC system.
You can see the lines and the hoses, and if you see any type of staining on the compressor
or on any of these components, where it looks like there's a potential oil leak, most likely
that is from a actual refrigerant leak, and that's gonna have to be addressed as well.
Your refrigerant's gonna be low.
That needs to be repaired before you add any refrigerant to the system.
And same with the condenser.
If you see anything that looks like a stain, it's most likely a leak, especially down in
the lower corner areas or even in the upper corner areas.
Let's talk about the EVAP core, which is located behind the firewall attached to these lines
right here.
Hot air is gonna go through the EVAP core and it's gonna cool it down, and that's what
gives you your cold AC air.
If there's no flow, then you're not gonna be able to cool that air down.
It kind of works similar to a radiator.
Some of the reasons why you may not have airflow is your cabin filter.
If it's extremely dirty and plugged up, it's gonna cause it to not flow as well, the AC
is not gonna work as good.
If the EVAP core itself is plugged up with debris, whether it's leaves, or pine needles,
or even pet hair, that's gonna cause it to not flow as good.
You may need to take a door off where the cabin filter goes and just get in there with
a vacuum, or even take the blower motor out.
You can pull the blower motor out, and on some vehicles, you may be able to access a
lot of area in there and just get in there with a vacuum.
Also while we're looking at the heating and air conditioning box, you wanna check the
drains.
If the drains are plugged up, you're gonna fill this up with water, you may notice some
water dripping on your feet or in the carpet.
If you have no flow, maybe your blower motor's not working right.
If you notice no air coming out of the vents, it could be the resistor, the blower motor,
there could be a wiring problem, or you could have a blown fuse.
Take a look at the drains, you wanna make sure they're not plugged up, they could have
pine needles or leaves in them clogging them up, and that's gonna cause water to fill up
in the heating and air conditioning box.
These drains are actually put there on purpose.
So if you ever notice in hot weather everyone's car looks like it's leaking water, that's
where it's coming from.
Another thing that could be wrong is the electrical system or even the fuses.
So check the fuses, check the relays.
If you have a blown fuse, there's gonna be something electrical wrong with the vehicle,
fuses don't blow on their own.
And the relays, if you wanna check those, a lot of times it's a good idea to just swap
it with a known good relay.
These relays have all the same numbers, so you could just switch these and see if it's
working after that.
It may be something as simple as a bad relay.
If all that checks out, most likely you have a leak in the system and you never want to
just add refrigerant to a system that's leaking.
It's just gonna leak out, you're wasting money.
I hope this video helped you out.
I hope it keeps you cool on those extremely hot days.
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