How to Fix Your Car Ac

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How to Fix Your Car's AirConditioner Have you been sweltering in your car because of a broken airconditioner? Here's a short guide to how air conditioning (AC)works why it !ight not work and what you can do about it"

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Understanding Car Air Conditioning

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Realize that auto AC is basically a refrigerator in a weirdlayout " $t's designed to !ove heat fro! one %lace (the inside ofyour car) to so!e other %lace (the outdoors)" &hile a co!%letediscussion of every s%ecific !odel and co!%onent is well outsidethe sco%e of this article the following ex%lanations of auto airconditioning should give you a start on figuring out what the%roble! !ight be" his should also hel% you work with the right%ieces if fixing it yourself or it will hel% you to talk intelligently toso!eone you can %ay to fix it"

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Become familiar with the major components to auto airconditioning

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o Co!%ressor his co!%resses and circulates therefrigerant in the syste!

o *efrigerant +n !odern cars this is usually asubstance called *,#-.a while older cars have r,# freonwhich is beco!ing increasingly !ore ex%ensive and hard tofind and also re/uires a license to handle" he refrigerantcarries the heat"

o Condenser his changes the %hase of the refrigerantfro! gas to li/uid and ex%els heat re!oved fro! the car"

o 0x%ansion valve (or orifice tube in so!e vehicles) hisis so!ewhat of a no11le and functions to si!ultaneously dro%

the %ressure of the refrigerant li/uid !eter its flow andato!i1e it"o 0va%orator his transfers heat to the refrigerant fro!

the air blown across it cooling your car"o *eceiver2dryer his functions as a filter for the

refrigerant2oil re!oving !oisture and other conta!inants"

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Understand the air conditioning process " $n a nutshell the

co!%ressor %uts the refrigerant under %ressure and sends it to thecondensing coils" $n your car these coils are generally in front ofthe radiator"

o Co!%ressing a gas !akes it /uite hot" $n thecondenser this added heat and the heat the refrigerant%icked u% in the eva%orator is ex%elled to the air flowing

across it fro! outside the car" &hen the refrigerant is cooledto its saturation te!%erature it will change %hase fro! a gasback into a li/uid (this gives off a bundle of heat known as the3latent heat of va%ori1ation3)" he li/uid then %asses throughthe ex%ansion valve to the eva%orator the coils inside of your car where it loses %ressure that was added to it in theco!%ressor" his causes so!e of the li/uid to change to a

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low,%ressure gas as it cools the re!aining li/uid" his two,%hase !ixture enters the eva%orator and the li/uid %ortion ofthe refrigerant absorbs the heat fro! the air across the coiland eva%orates"

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Your car's blower circulates air across the coldeva%orator and into the interior" he refrigerant goes backthrough the cycle again and again"

Fi ing the AC

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Chec! to see if all the R"#$%a lea!s out &meaning there'snothing in the loop to carry away heat( " 4eaks are easy to s%otbut not easy to fix without %ulling things a%art" 5ost auto,su%%lystores carry a fluorescent dye that can be added to the syste! tocheck for leaks and it will have instructions for use on the can" $fthere's a bad enough leak the syste! will have no %ressure in it atall" Find the low,side valve and with a gauge check the 67$ level"

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o 8o not use anything else to %oke in the valve to see if itwill co!e out this is illegal" $t's called venting"

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)a!e sure the compressor is turning "

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o 7tart the car turn on the AC and look under the hood"he AC co!%ressor is generally a %u!%,like thing off to one

side with large rubber and steel hoses going to it" $t will nothave a filler ca% on it but will often have one or two thingsthat look like the valve ste!s on a bike tire" he %ulley on thefront of the co!%ressor exists as an outer %ulley and an inner hub which turns when an electric clutch is engaged"

o $f the AC is on and the blower is on but the center ofthe %ulley is not turning then the co!%ressor's clutch is notengaging" his could be a bad fuse a wiring %roble! abroken AC switch in your dash or the syste! could be low on

refrigerant (!ost syste!s have a low,%ressure safety cutoutthat will disable the co!%ressor if there isn't enoughrefrigerant in the syste!)"

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*oo! for other things that can go wrong " he other sorts of%roble!s that the AC !ight be ex%eriencing include bad switchesbad fuses broken wires broken fan belt (%reventing the %u!% fro!turning) or seal failure inside the co!%ressor"

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Feel for any cooling at all " $f the syste! cools but not !uch itcould 9ust be low %ressure and you can to% u% the refrigerant" 5ostauto,su%%ly stores will have a kit to refill a syste! co!%lete withinstructions"

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o 8o not overfill: Adding !ore than the reco!!endeda!ount of refrigerant will not i!%rove %erfor!ance but

actually will decrease %erfor!ance" $n fact the !oreex%ensive auto!ated e/ui%!ent found at nicer sho%sactually !onitors cooling %erfor!ance in real,ti!e as it addsrefrigerant" &hen the %erfor!ance begins to decrease itre!oves refrigerant until the %erfor!ance %eaks again"

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Edit +ips $f you sus%ect bad wiring !ost co!%ressors have a wire

leading to the electric clutch" Find the connector in the !iddleof that wire and un%lug it" ake a length of wire and run itfro! the co!%ressor's wire to the %lus (;) side of yourbattery" $f you hear a loud C4AC< the electric clutch is fineand you should check the car's wiring and fuses" $f you getnothing the electric clutch is bad and the co!%ressor willhave to be re%laced" $deally if you can do this test while thecar is running you can see if the hub s%ins" ake care tokee% fingers and loose clothes away fro! !oving %ulleys andbelts" hat would rule out a clutch that actuates %ro%erly butthen sli%s so badly it won't generate %ressure"

Your syste! will have a light oil in it" $f your car has an air conditioner leak even though the drain

%i%e is clean so!e water !ay have entered the AC syste!during a drive through rain"

Another %ossible re%lace!ent refrigerant is HC# a which isused /uite a bit !ore in 0uro%e" $t %erfor!s better than *,#-.a or *# " $t is !ore fla!!able" HC# a is illegal in !any

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="7" states including Arkansas Ari1ona ConnecticutFlorida $daho $owa $ndiana ebraska >orth 8akota +klaho!a exas =tahirginia &ashington &isconsin and the 8istrict of

Colu!bia" HC# a has a lesser environ!ental i!%act than*# or *#-.a but since HC# a contains hydrocarbons itcould contribute to volatile organic co!%ound ( +C)e!issions" his substance !ust be ordered on the $nternetas local sho%s do not see! to stock it" he issue is thatsho%s will not work on a car that has other refrigerants in it"7%ecial e/ui%!ent is needed for each ty%e of refrigerant'srecovery" 7tandard *# or *#-.a is a safer choice"

7o!eti!es the %roble! is not always about the refrigerant"here !ay be a %roble! with heat radiation fro! nearbyengine which is very hot and decrease the AC efficiency and%erfor!ance" You can try to wra% 2 isolate the cold AC %i%enear the engine to sto% engine heat radiation fro! affectingthe %i%e and increase ac %erfor!ance overall" @#

Edit ,arnings 4ook out for !oving fan blades and fan belts: You !ay not find a re%air facility that will si!%ly to% you off if

they sus%ect that you need to re%air a leak first" $f youre%aired the leaks and failed co!%onents yourself it is legalto recharge the syste! with #-. without a license but not *,# " However getting a license to handle *,# is easy onlineand runs about B ")

$f you have any reason to sus%ect that your refrigerant hasleaked out co!%letely (the 8$Y %ressure gauge you bought atthe %arts store reads %siD the co!%ressor won't engagebecause it !ay be sensing no %ressure in the syste!D youchecked the gauge and have no 67$ level ) then you arebest off taking it to a %rofessional unless you are fa!iliar withwhat you are doing" As a general rule of thu!b you are%robably not fa!iliar enough if you are reading this article"he reason for this is that a co!%letely de%leted refrigerantsyste! has no %ressure to kee% air and !oisture fro!

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co!ing in through wherever the refrigerant leaked out" Airand !oisture are %ossibly the two biggest ene!ies of an airconditioning syste!" he ways in which they can do har! areoutside the sco%e of this article but suffice it to say that it is

not okay to have a significant a!ount of either in the lines"he receiver2dryer unit must be re%laced in a case like this asyou can al!ost guarantee that it has absorbed enough!oisture to be co!%letely useless and before refilling thesyste! it must be evacuated (%ulling a vacuu! on thesyste! effectively re!oving nearly all air and !oisture fro!inside) with the %ro%er e/ui%!ent which few 8$Yers are likelyto have access or knowledge to use" 4et a %rofessionalhandle it and you !ay get away with %aying for a fixed leakand an evacuate2recharge" ry to fix it yourself and a few!onths down the road you !ight wind u% having to %ay forthe sa!e evacuate2recharge service %lus re%lace!ent of asei1ed co!%ressor as well as a new condenser eva%oratorand ex%ansion valve2orifice tube because the co!%ressorsent shards of !etal throughout the entire syste! when itdied"

Ee extre!ely cautious about converting your old *,# syste!to *,#-.a" he *,#-.a conversion kits sold at Auto 6artsstores and even &al5art are called 3Elack 8eath

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>ote that the above warning is controversial" 7o!ere%air!en clai! to have converted hundreds of vehiclesfro! *,# to *#-.a without any %roble!s or issues orfailures after conversion"

HC# and *,#-.A are non,fla!!able at a!bientte!%eratures and at!os%heric %ressure but both !ayco!bust at high %ressure and te!%erature under certainconditions (in contact with certain reactive !etals)" Eoth alsodis%lace oxygen so do not release a lot of the gas in a s!allnon,vented area under %enalty of as%hyxiation"

>ever connect refrigerant cans oil or leak,detector cans tothe 3high %ressure side3 of the syste!" his is often !arkedwith H or H$ H or a red connector ca%" Cans can ex%lodeand that would hurt"

7tay away fro! !a9or leaks of refrigerant" As it vents it willget cold enough to free1e your skin resulting in frostbite"

Checking for refrigerant by %oking so!ething in the fitting andlooking for venting !ay be illegal if it releases refrigerant intothe at!os%here" (6lease don't do this with *,# es%ecially:)&hile it is not illegal to to% off a leaking syste! you !ustcheck your local regulations as in so!e cases there is astate or local law against it due to the %ossible e!issions" @ enting refrigerant even *,#-.a is illegal in the =nited7tates so act accordingly"

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