rev up your engines, today I'm gonna talk about a common car air conditioning
problem and how you can fix it the problem is this say the passenger side
is blowing cold air but the driver's side is not blowing cold air, now a car
like this 94 Celica it's a simple air conditioning system it doesn't have dual
controls or anything it's got AC you turn it on or off then it's often a very
simple problem just being low on refrigerant now this may be a 26 year
old car but I've only had to add refrigerant one time now here's an old
broken AC compressor all air conditioning compressors leak
somewhat over time the fan belt spins it spins a shaft the shaft has to have a
seal on it if that seal was perfect it would run dry burnout and all the
freon would leak out, they all leak a little bit of refrigerant and AC oil in order to
lubricate that seal now in a case of Toyotas it's often a very slow leak I
mean I had to add refrigerant to this thing once in 26 years so it's a
very slow leak but when it leaks out enough it will affect the performance of
your air conditioner if you understand how our air conditioners work it's
totally logical the compressor compresses the refrigerant it's hot then
it pushes it to the condenser in the front which gets rid of the hot air, hot air
gets blown away then that gets sucked into the evaporator inside the dash that
expands and gets cool there then it's sucked back into the compressor
in an endless cycle and since most cars have the evaporator on the passenger side if
you're running low on refrigerant the passenger side can still blow somewhat
cool but by the time it makes it over to the driver's side it's not cool anymore
so just being low on refrigerant can make it do that so if you know how to
use AC gauges you can hook them up to see if your low on refrigerant and if your
are you can add some and if you don't you can just pay a mechanic to check it it
doesn't take five minutes and here's a money saving tip guys are always trying
to sell people stuff say your low on refrigerant they'll say oh wow your
compressor is leaking you need to buy a new one before you spend a whole bunch of
money if it's been years or if the system never has had any refrigerant and
first just add some refrigerant I've done that on cars and sometimes they
last five six years before they stopped working to get in then you just fill
them up once every five or six years always start simple and work your way up
and if you do add refrigerant if your system doesn't have any of that leak dye
a lot of them are made with leak dye but if it doesn't you can add a little bit of the
leak dye in to so then when it finally leaves out you'll see the dye coming out
of the area and you'll know which one is leaking now many cars just have the
single AC system leaving this relatively new matrix it's got a single system
called on one side not on the other odds are you just low on refrigerant but if
you have a more modern dual control system where you control the left side
and the right side independently like this lexus then things can get
complicated because here as you can see you can adjust the driver's side from
cold to whatever temperature you want and the same thing on the passenger side
you can adjust that too, now here of course you're doing the level of
sophistication all run by computers that can make your head spin but basically
here's how it works the computer system take the inputs there's temperature
indicators inside and inside the dash are blend doors that open or close to a
certain degree to make it whatever temperature you sided here now of course
a lot of its fantasy you put it on 69 degrees it's not gonna stay exactly 69
but you can make it soap one side can be as hot as you want in this case will go
too hot or the other side can be as cold as you want
in that case the passenger side it would turn the duct to the heater open using
the actuators that open the door so you'd have hot air blowing here but on a
driver side it would only open the actuator for the AC system so cold air
would come out here and you can guess what happens with computer actuated
systems when they break I mean thank heavens this is a Lexus they hardly ever
break so I don't have to mess around with it but when they do break
unfortunately you're gonna have to find a guy like me that has one of these
really fancy computers to access that data to do bi-directional testing I'll
show you how it works on this Lexus well the beginning is easy it just plugs into the
data port plugged in then we put on the car and we're looking for stuff for the
air conditioning system well the air conditioning system on this particular
one it's part of the body system so we'll
push body it's got all kinds information I could join that the magnetic clutch is
off now cuz they see just the cycling and on a second they're not back on
again you get all kinds of data you can
analyze and as various active tests that you can do to not question you don't
have one of these fancy scan tools good luck trying to figure out what's wrong
it's one of those blend doors is breaking plus most of the time it'll be
something like an actuator motor you gotta take the whole damn shit a car
apart to access it repairs can easily top a thousand dollars on many cars
these days of fun of those stupid little doors breaks but it is another tip that
might save you a ton of money let's say you're having electrical problems the
first thing I advise all my customers to do is have the battery load tested and
have the alternator load tested many auto parts stores do that free you can
even buy a quality thing to test it you stop these days for seventy eighty
dollars you know buy an expensive one like this midtronics this thing was over
eight hundred dollars and it was new today you can get 60 70 $80 versions
from other companies that work quite well realize that all
computer-controlled systems require a steady accurate supply of voltage if the
voltage goes too low or too high squirrely things can happen if you're
cold on one side hot on the other maybe there's just not enough power going to
the other side always check the battery and alternator
before you start spending a ton of money doing computer analysis and turn the
dash apart and here's another trick let's say this side is blowing called
and this sides blowing high well the extra weird is dropping here sometimes
just going back and hitting the dash really hard if it's a stuck actuator a lot of
times they'll unstick I've had some customers that drove cars years that way
when one went cold on one side and not the one side they give it a good whack and it would start working
and realize those stupid doors are generally made out of plastic and they
can stick as they age and if hitting it works what the heck
so now you know a bit more about car AC systems and what you can do if you've
got hot air blowing out on one side but cool air come out of the other
so if you never want to miss another one of my new car repair videos, remember
to ring that Bell