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whynotthinkwhynot 04-13-2009 12:27 PM

General Ford Focus AC Troubleshooting and Repair
Thanks to Bluefront, ShamrockSVT, Aironjack, and Marde for their help in writing this tutorial. Anyone else is free to help or correct my information, for example, the fuse and relay locations might be different in SPI and Zetec, or in different years of Foci. Please PM me to correct any discrepancies you find so we can provide the correct information for our members.



*On a hot day with the AC system running, there can be 200lbs+ of pressure in the lines. Whenever working around refrigerant, use good eye protection. If you ever witness an explosion of the system (it happens), you'll know what I mean. It is best to work on AC systems in the shade, especially during charging.

* Do not connect your gauges to the high and low side at the same time. The high side will bleed into the manifold and mess up your reading on the low side even if it's off, and if you open both valves you might cause the manifold to explode.

*You can get frost-bite of the fingers very quickly if the refrigerant touches bare skin, or you touch the can in the right situation. Light-weight gloves and care to avoid misconnections will help.

*NO SMOKING! Older R12 when combined with tobacco smoke would create a compound similar to cyanide gas. R134 is similar enough that I think it would be wise to extend this warning to anyone working on a R134 system. While the chances are low that there will be a problem- it's certainly not worth taking the risk.

EPA Information: This information is for people who have leaks in automotive AC's which are draining their refrigerant. Continually adding refrigerant to a leaky system can harm the environment. R134 is friendlier to the ozone, but contributes to global warming as a greenhouse gas. There might be EPA regulations in your area preventing you from purchasing refrigerant without a license. Please check your local laws, and if you have a leak, please read all of this article and repair your system instead of putting cans in every couple of weeks. Link to EPA Info on Auto AC

Capacities, Relays, and Fuses 05-07
PAG oil: 7 oz
R-134: 26 oz
Fuse: 21, under hood
Relay: R11
Diode: D3
For earlier Foci, please check your owner's manual for fuses, and look for a sticker on the radiator cover giving the oil and refrigerant capacity until we get those listed here.

Description of parts and operation:
Starting at the compressor, refrigerant is pumped to the condenser, located in front of the radiator, where it is cooled. From the condenser, high pressure refrigerant goes through the high side (small) hose into the evaporator located in the cabin air plenum under the dash. It passes though the orifice tube that serves as a filter and pressure holding device. In the evaporator is where the magic happens. Refrigerant passed through tiny holes into the large coils of the evaporator allowing it to expand and cooling the evaporator. Air is blown across the evaporator, and you get cool air through the vents in the dash. On the other side of the evaporator, the low side (large) hose transports the gaseous refrigerant to the accumulator located in front of the radiator. The accumulator sucks moisture out of the system, and homogenizes the refrigerant mixture. The low side is also referred to as the suction hose, and supplies the compressor with gaseous refrigerant. In the compressor, refrigerant is compressed back to hot high pressure gas and the process starts all over again.

Electrical Troubleshooting:
For those of you who discover you can add a can and get your AC to work for a week or so, you should only do this once before repairing the system as described later. You can skip the electrical troubleshooting section since you know your problem is due to a leak.

The compressor is engaged by an electric clutch located on the front of the compressor. If you can watch it while the engine is idling, when the compressor cycles you'll see the outside of the pulley start turning when the clutch is engaged. First, check the AC fuse to make sure it's not blown. Secondly, make sure that the AC clutch electrical plug is connected, and the wiring to the clutch is not damaged. Once verifying that there is no damage to the power circuit of the AC clutch, we move on to the electrical controls on the AC system.

There is a control circuit that switches the AC relay to prevent damage to the system. When you turn on your AC, it sends power through the low and high pressure switches on the AC hoses and then to the AC relay in the box under the hood. You can test these switches using an electrical continuity tester. The high pressure switch can be tested regardless of the system being charged. It should show electrical continuity between the pins on the switch itself, otherwise the switch needs to be replaced, and the system will have to be recharged. The low pressure switch can only be tested if system has a charge or is being charged. You will not be able to charge a system with a bad low pressure switch because the compressor will not come on. The only time I'd test this is if I hooked up a can, and the compressor did not come on- then test continuity on the low pressure switch. To test the relay itself, I replace the AC relay with a similar relay that I can verify works- either of the headlight relays are the same part as the AC relay. Put the AC relay in the headlight slot, and see if the lights work.

If the electrical controls check out, you have a charge, and there is power on the 86 pin on the relay when the AC is switched on with the engine idling- then you could have a bad AC clutch. Using a digital multimeter set to ohms or continuity, test between the pins on the AC compressor clutch. If you do not get a resistance reading or continuity, then the clutch is bad. You do not have to break the system down to replace the compressor clutch, but that makes it much more difficult because you can't remove the compressor completely from the vehicle. You should be able to remove the compressor and get it down on the ground under the car, but you'll have to disconnect the hoses in order to get it on a bench. It is not impossible to replace a clutch with the compressor removed from the engine, but still connected to the hoses. It will be difficult, but it will save you the trouble of recharging, replacing O-rings, and vacuuming the system. Please check your shop manual for a description of how to do this. If the compressor is very old, it might be worth it to just replace it and go through the whole system to insure a longer lasting repair.

Finding and repairing leaks:
I do not recommend stop-leak additives at all. All my experience with AC stop-leak has resulted in the replacement of the compressor shortly afterwards. What happens is that the system still leaks refrigerant to the point where it won't run, then the stop leak gums up the compressor as the system loses refrigerant. The best way to fix a leak is to locate it and repair the system. You can purchase leak finder, and even install cans of R134 with leak finder in the can. This is a dye which circulates in the system and is visible under UV light while wearing specially tinted goggles. Kits are readily available. For those who have slow leaks, it would be wise to purchase a kit, and recharge with a dye infused refrigerant to be sure of where the leak is.

For the rare leak from an evaporator, you will need to rent an electronic leak sniffer, or visit a shop for the repair. Depending on the size of the leak you might be able to smell refrigerant through the vents. Fortunately, this doesn't happen often, but it is possible. Condenser leaks are more common than these due to flying debris from the road. Usually you'll be able to hear these leaks when adding refrigerant to the system. All you can do is replace the condenser.

Dyes are most efficient at locating leaks around hose fittings and connections. IMO, you should always add dye to the system during recharging to help diagnosing future problems. Most systems can be repaired by replacing the O-rings inside the hose connections, but you should check your hose fittings for leaks visually or by using your hands. PAG oil is clear, thin, and very slick. The majority of hose leaks (not O-rings) will occur at the crimped hose fitting that converts the hose from rubber to metal. For those of you who have very slow leaks which take a year to affect the system, dye can help you locate which hose fitting needs repair, but you should still consider replacing all the O rings when you have the system down to repair the hose. Hoses are the next most expensive part of most AC systems aside of the compressor. In some cases, the hose changeover from metal to rubber can be repaired, NAPA offers this service, and can save you a bundle by replacing the fitting to repair the leak. If not NAPA, search your local Yellow Pages, or just simply ask some of the more knowledgeable parts guys at your local stores.

Leaks can occur anywhere in the system, but bad O-rings are the most common cause. Any time you have the system discharged, you should consider replacing the O-rings whether the leaks come from those connections or not. All Ford AC systems use a quick-connect snap ring system. To release the snap ring, you'll need any one of several special tools. I use the cheaper tool where you simply size the tool to the fitting, slide it in until it stops, then pull on the other side of the hose to disconnect. On the male side of the hose, you'll see 2 O-rings in the hose. Pull these out, match the size to new O-rings from a multi-kit, or a car specific kit, and replace the rings. Be sure to lubricate the O-rings with PAG oil which should be available in a non-pressurized can. This is how you'll replace the rings at the condenser, the dryer, and the evaporator, and any other hose connection you locate when visually inspecting the system. Make sure to get them all because Murphy's Law says that the one you don't feel like doing because it's so hard is the one that is leaking. There are 2 O-rings on the hose connections for the compressor that will probably have to be ordered specific at the parts counter. When reconnecting these hoses, make sure that the mount sits flat, and is turned like it was when you disconnected it before tightening the connection down. It is easy to damage that fitting's nipple if you're not careful, and crank the bolt down when it is not completely lined up.

The accumulator will have to be removed in order to replace the O rings, one side of the dryer will be male fitting, and the other side will be female. There is also the orifice tube to consider any time the system is depressurized. It is located close to the firewall in the high side hose just past a coupling in the metal part of the line. Use 2 wrenches to loosen the coupling, and the orifice tube will be in the straight metal line between the coupling, and the evaporator. You won't be able to see it, but you can feel the end of it with your little finger. There are just 2 tiny O rings that hold the orifice tube in place, but you might have to twist it to break the rings free. I would replace the orifice tube any time I have the system down, and especially if the compressor has gone bad. Likewise, the accumulator should be replaced anytime the system has been exposed to the atmosphere. For the few with low mileage AC problems, or recently replaced accumulators where a slow condenser leak happened after recharging- you can get away with not changing the dryer if you repair the system ASAP as long as you vacuum the system down as described later. I've done this before without problems even though it's not recommended.

Vacuum testing, flushing, and recharging:
Now we get to some expensive tools, but you will be able to rent the most expensive tool if not all the tools needed. You'll need a vacuum pump, a set of R-134 gauges, and a recharge line to penetrate the can and connect to the gauges.

Before vacuum testing, you can purchase a quart of AC system flush. It costs about $20, and most parts stores have it. This would be most beneficial if you have parts like the condenser, evaporator, and hoses removed from the vehicle. You simply pour it in one side, and then use compressed air to blow it out the other side. If you really want to, you can let it soak in there, or do it multiple times. I'd consider this if you have a really old condenser, or you think there might be dirt in the system from extreme condenser damage.

First let's familiarize the parts of the gauges, and the functions. Your gauges will have 2 sides, colors might vary with manufacturer. The only one you really need to be concerned with is the low side which will read up around 120 psi. The hose that should be on that side will connect only to the low side port located in all Foci under the passenger fender just in front of the hose that connects the accumulator to the compressor. There is a valve located under the gauge that controls the hose inlet to the gauge manifold. Some hoses also have a cut off valve which will stop the flow through the hose. Gauge manifolds will also have a center hose inlet for charging and vacuuming. If you are not using part of the gauges, like the high pressure side, then be sure to have it's valve closed, and the hose connected to a stop on the manifold as well as any hose valves closed. There should be a stop to connect the other side of the center hose to block it's manifold inlet. Please read any directions that come with your hose set to be sure you are operating the gauges correctly and safely.

Before recharging, you must vacuum test your system. This serves 3 purposes: 1) removing any moisture and oil left in the system 2) testing the system for leaks 3) helps suck down that first can of refrigerant. If you're not concerned with the ozone layer, then surely you're concerned with spending more money on recharging the system over and over until you fix all the leaks. Some parts stores will allow you to rent a deep cycle vacuum pump. Read the directions that come with the vacuum pump before using it because there is a relief valve that must be opened slightly to allow moisture to exit the pump, then closed to pull a vacuum. Connect the low pressure gauge to the low pressure port, open the gauge manifold valve on the low pressure side, and connect the center inlet to the vacuum gauge. Now, start your vacuum pump as per the directions, and vacuum the system down to -30 psi or as close as possible. The object is to maintain a vacuum on the system and monitor it's negative pressure. To disconnect the vacuum pump, first cut off the hose valve, then remove the line from the vacuum pump. Connect the center line to it's stop on the gauge manifold to seal it, then open the hose valve again. It's very important to orient your view on the gauges so that you can tell if the needle moves even slightly. Check the reading on the gauge, and go watch some TV for a while. Wait at least 30 minutes, and return to check the gauges again. If you think the needle has moved, wait another 30 minutes and check it one more time. If the needle has not moved, then the system is sealed properly and it's time to recharge.

The first thing to add to your system is the oil charge. It is important to add the oil first because the compressor won't pump efficiently without it. Start the engine, and put the AC on Max (recirc). Some manufacturers offer oil mixed with refrigerant and dye called a "First charge", and then there are pressurized oil charges with small amounts of refrigerant. These are the ones to use with the methods I've described. You will want to put these in the system without going through the gauges so you can invert the cans allowing all the oil to be sucked out of the can. Keep in mind the amount of refrigerant and oil you are adding. If you add too much oil, then that will reduce the amount of refrigerant in the system. Too little, and lubrication, suction, and compression could suffer. The amount of oil in the can will be written on the back of the cans. A small amount of oil could be trapped in the system, so if you're an ounce off- it's not a big worry unless you've flushed the system. After the oil comes the refrigerant. Keep in mind the refrigerant in the oil charges you've already added. It should not take more than 2 cans to refill a Focus AC, going a little over or under is ok. The last can I would add these through the gauges using the center inlet if you have a can hose that will connect to the gauge manifold. This way you can keep an eye on the pressure when the compressor cycles. You want to be somewhere between 30 and 40 psi. Once you get above 30, use a thermometer in your vents to gauge the temperature of the air. Too much refrigerant will raise the temp just like too little will do. One method is to add a little refrigerant and check the thermometer in the vents. After the compressor is running continuously, add refrigerant in spurts until the temperature stablizes. Continue to add until the temperature drops slightly, or you have reached the recommended refrigerant amount. Do not go over 40 psi with the compressor cycling. With the gauges on the system, you'll notice that the pressure will increase tremendously (the high side and low side try to reach equilibrium) when the compressor is not cycling.

There is a relationship between low side refrigerant pressure and temperature at the evaporator. Basically the psi = evaporator temperature in F. You want the pressure to be above 32 psi with the compressor turning fast- engine at highway rpm. You want to find a good point between the 3k rpm psi, and the idle psi. You don't want your idle psi to be much over 40 as that will make the cabin hotter in heavy traffic. Too much refrigerant will also cause stress and strain on the hoses, hose fittings, and O-rings that will cause premature failure as well as raising the temperature of the evaporator. Now you can understand why simply throwing a can in a car that's not cooling well is not always going to "fix" the problem.

Bad Compressors
Well, if your system has been losing refrigerant- it has also been losing oil. Loss of oil will cause premature wear on the compressor, as well as reducing it's seal. Even a good compressor needs oil to do it's job. If your compressor is bad, you will have some trouble getting the first charge to go in the system. If it took a very long time for the first charge or additional cans to be sucked up by the system, then you should hook up the gauges to check the operation of the compressor. You'll need to hook up both the low and high side of the gauges to their appropriate fittings. Then turn the AC on Max with the engine idling. Compressors go bad one of two ways- either it will turn and not compress, or it will not turn at all. The last of which you'll likely hear as belt squeal when the compressor clutch kicks in. The first one you'll see in the gauges. If the compressor kicks on, but the high and low side of the gauges remain equalized, or there is little difference between the two, then the compressor has gone bad internally. You should be able to tell if you have a good or bad compressor when you've put in the first can of refrigerant. It's a bummer that you have to waste a can of refrigerant and the oil charge to discover if you have a bad compressor, but keep in mind it will still cost you less than if you'd had a shop discover this for you. Also, keep in mind that the first can takes a while to get into the system because the compressor will be kicking off due to the low pressure switch, with a good compressor you'll see the low side drop below 20 psi, and the low pressure switch will cut off the compressor clutch.

Alternative Refrigerants: There have been some new refrigerants developed to replace R-134 because it is a greenhouse gas. Unfortunately, these refrigerants are derived from flammable hydrocarbons, and the EPA questions the safety of these in automotive applications because the condenser is located in front of the radiator. These refrigerants are much more efficient, and so require less refrigerant for greater cooling ability. Please read all the information and ask all the pertinent questions from the manufacturer that you can think of before considering using this refrigerant. Although it is combustible, it has a lower flash temp than R-134. I also recommend reading the EPA's website on the legality of these refrigerants very carefully as the legal mumbo jumbo can be difficult to understand. Basically the EPA mentions that Europe is using these refrigerants, we might be, but convert at your own risk considering the flammable nature of the refrigerant. EPA Legal page and FAQ on hydrocarbon refrigerants Here is a link to the EPA's approved alternative automotive refrigerants page

Automatic Adjusting Orifice Tube (VOV):
Here's an article explaining how these work- the part is more expensive- $30, as compared to $3. It makes AC more efficient at cooling in stop and go traffic, and will likely save money. **Since I wrote this, I've been advised by many professionals that they tried VOVs, and that those did not work for more than a year**

If care and attention is taken to all these steps you should have an AC system that will stay cool for several years. Personally, I'm lazy and cheap, and that's why I recommend going the extra mile to find the leak, then replace all the O-rings (even if these aren't the cause of the leak), the orifice tube, accumulator (if needed), and vacuum the system to insure it's integrity. That seems like a lot to do, but it's much less work to do this correctly one time instead of doing it every summer for a new leak. I hope this saves anyone who can suffer through the tutorial some money, and also helps save the environment by stopping "a can every month" AC gurus from punching a bigger hole in the ozone over Toronto.

bluefront 04-13-2009 03:29 PM

Good idea.....A/C systems can be difficult to repair in your driveway, with a minimum of tools, but not impossible. Your initial write-up covers quite a bit.

There are a few cautions you should be aware of.......On a hot day with the AC system running, there can be 200lbs+ of pressure in the lines. Whenever working around freon (now called r134), I recommend using good eye protection. If you ever witness an explosion of the system (it happens), you'll know what I mean.

And you can get frost-bite of the fingers very quickly, if the refrigerant touches bare skin (or even the can in some situations). Light-weight gloves will help.

The little cans of refrigerant you buy, are meant to go into the low-side port. They will not attach to the high-side port. Basically follow directions that come with the can. The compressor will suck in the refrigerant with the engine/compressor running.

If your compressor will run, but the system doesn't get cool enough, a can of refrigerant may fix the problem. Many systems will leak a little refrigerant normally, so adding a can every 2-3 years, may not indicate anything serious.

On the other hand, if your compressor never turns may have a serious problem. And just adding a can of freon through the low-side port may be impossible, using normal methods. The compressor won't turn on if you're completely out of refrigerant (read the first post in this thread). Take a cap off the port, and stick a screw-driver down the port, and see if anything comes out. You should get a big blast of refrigerant if there's anything in there.

There is a work-around if the system is completely empty. Hook up a can of refrigerant to the low-side port, open the valve on the can, and set the can in a pan of hot tap water. The heat will force the refrigerant into the system, even though the compressor is not running. You don't even need to turn on the ignition to do this. You may have to put more hot water in the pan, and this takes a few minutes, but eventually you can get the system recharged this way.

Once you get two cans in the system....the compressor should turn on, and the system should cool again. Unless you have other problems......

More to come.

bluefront 04-14-2009 11:12 AM

How to.....find leaks. If you keep losing freon (Refrigerant) and have to add a can frequently, it'll pay to find where the stuff is escaping. And it can leak anywhere from the condenser in the front, to the evaporator under the dash.

There are several ways to do this.....

Visual inspection. As freon leaks out, some compressor oil comes along with it. The freon evaporates, but the oil doesn't. It leaves a stain, and dirt collects on it. So...inspect the entire system carefully. Any oil stain on the compressor, the condenser, etc., indicates a freon leak at that location.

Listening for a leak. If your leak is big enough, as you try to add freon through the low side port, you will hear a leak hissing. If a rock punctures your compressor/condenser, you'll probably find that leak as soon as you add freon.

Electronic methods......I used to use these things frequently. They're little hand-held machines with a suction probe. You move the probe around the sucks in air and if it detects freon it beeps. But none I ever used worked too well....too many false alarms. They have been mostly replaced by dye in the freon.

The dye method......and maybe the easiest/most accurate. Most of the time these days, cars come equipped with dye in the freon. You can buy cans of freon with dye. The easiest way to see this dye is by using special glasses and a special light (I've seen a kit at O'Rileys for this). You simply go around the system with the light (it's easier to see at night). A freon leak will glow orange or green (maybe other colors). This method can pin-point a leak in the evaporator (the most difficult leak to find). You climb under the car, find the drain hose for the evaporator (on the pass side firewall), and shine the light on it. If any dye traces show up, you have an internal leak in the evaporator.

Those are the four methods I have used over the years to find leaks.....there may be others. I'm not sure if all the different Focus models come with dye in the freon. It's easy to check....take the cap off an access port. Stick a screwdriver down the port and release a little freon....shine the light on it. The port will show the dye if there's dye in the system.

As careful working with any refrigerant (eye protection for sure).

bluefront 04-14-2009 06:47 PM

Harbor Freight is a good place to find tools to work on your AC system......these may not be the highest quality tools around, but for occasional use on your own or friend's cars, they'll work as well as SnapOn (the expensive stuff).

Take a look at these tools. Considering an hour's labor at the dealer can be $100, buying tools like this could save a bunch of money.......

And here's an example of a a dye leak detector kit. A lot of different kits can be found with a google search......this is an expensive version. You can find them cheaper.

penguin 04-14-2009 11:19 PM


Seriously, the best write-up I have ever seen on auto air conditioning!

whynotthinkwhynot 04-14-2009 11:56 PM

Thanks, I'm still at it. I hope to add pics later of tools and locations of ports and parts in the different vehicles if I can get some help from other FF's.

I'm asking everyone to please read it carefully and help me edit or inform me what's needed. I especially need help with the older Foci capacities.

I do these things on my own vehicles, and this is the culmination of many years of learning and asking questions. Some things might not be exactly correct- especially when it comes to determining if a compressor is bad or not. The only way I know to tell is if there's a charge on the system and you compare the high side gauge to the low side gauge and don't see a change or the darn thing locks up and rips the belt to shreds. I'm also not exactly sure how to replace the clutch on one of these, but I'm not sure I want to go that far because by the time the clutch is bad most people should consider replacing the compressor.

It's going to take a while, but I think I've gotten most of the written part down now with the exception of some editing.

Thanks again, and please feel free to add anything you feel is pertinent [thumb]

bluefront 04-15-2009 05:15 AM

Concerning the compressor's attached to the compressor for sure, but it has it's own bearing assy. This means that your compressor can be completely locked up, but as long as the clutch doesn't engage, the belt to the compressor will still turn freely.

If you're driving along in the summer with the AC on......if you hear a belt screeching, immediately turn off the AC. If the problem is a bad compressor, the belt noise should stop. But you could also have a frozen bearing in the compressor clutch.......if this happens you may be S.O.L.

Depending on the year/model/ may be able to replace just the compressor clutch if it's bad. But the job is not easy, and usually requires special equipment (pullers) to separate the clutch from the compressor.

How to tell if the compressor is locked up......easy enough. You find a socket to fit the nut on the end of the compressor shaft. This is accessible in the center of the compressor/clutch pulley. With a short ratchet you should be able to turn the compressor shaft (turning clockwise) easily......turn it several times and the compressor should be ok.

A better idea is to buy a compressor with the clutch already attached. Then the job is relatively easy. You remove the compressor assy, replace it with the new one, evacuate and recharge the system. However.....if the whole problem was a bad/locked-up compressor, debris may have gotten into the system. The fix for that is expensive.....a new receiver/drier and an AC system flush.

If you've gotten to this may be better to have a shop do the job. This way you'll have a warranty on the fix. Tough call.

aironjack 04-16-2009 03:28 AM

Hi whynotthinkwhynot,

As always your efforts for helping people and doing these mad writeups are amazing, mad props for you man!

As you know my Focus doesn't have AC since long time ago. I have been reading and documenting myself on this field, so I will try to help you out with this.

First, I bought a set of AC pressure gauges for fixing my car. Hopefully, I will take as many pictures as I can of the system tomorrow morning, it's an SPI 2001. I will send you the details of the AC system in this model too.

Here is my feedback on your tutorial.
1.- The description on the functioning of the AC system is a little bit confusing to me. Everyone usually starts explaining the whole system starting at the compressor. It is also not very clear the way the refrigerant goes in.

Another thing is that new AC systems don't come with a receiver/dryer if I am not mistaken. They have an accumulator which is located in a different part of the system. As well as the expansion valve was replaced by the orifice tube.

Here are some good pictures I like for understanding the functioning:

Here is a picture of the AC system inside a car, so people can see what are we talking about. Locations really differ among cars, as you know, but still good.

I can only find pictures or graphs of the old style AC. Tomorrow, I will try to find the modern version.

2.- For the electrical troubleshooting part. I would like to say, that is good to start from the end to the beginning. I would start checking if the AC clutch switch is getting current, if not checking the pressure switches...

I found a youtube channel from a guy with nickname richpin06a. The guy explains electrical and pressure AC troubleshooting in detail on a Saturn. Very good material:

YouTube Video
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YouTube Video
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YouTube Video
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YouTube Video
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3.- I think you didn't say any place to lubricate the o-rings with ac oil before installing.

4.- A way to know how much debris your system has is observing the orifice tube.

5.- When you vacuum the system are you discharging it at the same time?

Right now I am pretty tired, but I will re-read the whole thing tomorrow and try to add more stuff to the discussion.
One thing I want to comment is that it might be a good idea to classify the troubleshooting in different parts to make it less confusing.

Sorry for my English, too tired and too Spanish for doing better.

I hope it helps, reputation for you man!

bluefront 04-16-2009 06:00 AM

^^^More good AC info, but somewhat complicated to the average guy trying to trouble-shoot the system in his driveway. My replies to this thread will concern mostly DIY repair, concentrated on simplicity.

Yes the reciever/drier of previous years has been replaced with an accumulator. But to the average guy the two things perform a similar function.......I suppose you can consider both as being the system filter.

Evacuation vs Recovery......They are different. When your system is totally empty of refrigerant, you should evacuate it of air/moisture before installing a new refrigerant charge. Those vacuum pumps in the Harbor Freight link will do that.

Recovery is a different procedure. Recovery is when your system still has a refrigerant charge left in it, and you need to remove something (say the condenser). In the old days we would just release the freon(refrigerant) to the atmosphere. Well times have changed.....and there are new laws to deal with. Releasing refrigerant to the air is technically illegal in most places. If a repair shop does it, they get in big trouble. your driveway, doing the same thing is up to the owner. I've never heard of anybody getting in any trouble for the act. Although Al Gore would have a cow......

To do a proper recovery requires a special expensive machine that sucks out the freon, stores it in a container for reuse. So if you go by the book, you need to visit an AC repair place every time you remove a part of your AC system. That's the legal way......I'm sure different states have different laws concerning this matter.

The r134 we use these days is relatively harmless.....compared to the r12 of the past. [dunno]

Oh.....U-Tube videos are nice, but are impossible to view for the poor guy using a dial-up. That's me and others who repair their own cars.

whynotthinkwhynot 04-16-2009 07:30 AM

Aironjack- thanks, I'll make a note of that. Apparently my understanding of the operation of the AC system was a little backwards according to that diagram. I can't rely on all the people who have told me things in the past.

1) Refrigerant goes in through the low pressure port located in the passenger fender under the plastic inner fender well just behind the headlight. I thought I explained that well enough in the recharging section.
2) I can rearrange that so that you'd start checking at the relay if that's not how I wrote it. Yes you should start at the beginning in electrical testing. Pin 86 on the AC relay should have power to ground, power on one side of the relay, if no power check fuse. As long as pin 86 on the AC relay has power, then the rest of the electrical control system is good. That would be a more concise test than the way I wrote it.
3) Ok.
4) If you have the system down to remove the orifice tube, then it should be replaced regardless. The orifice tube traps debris, usually metal shavings from the compressor, and prevents it from reaching other areas of the system.
5) If you're following my directions, then once you reach the vacuuming stage the system will have been discharged a long time ago. As I wrote at the very start, that tutorial is for people who have AC system leaks, not for people who have a charge. I've been trying to add things for people who have charged systems that aren't working, like how to tell your compressor is bad with gauges, to complete the explanations. As for anything else, the vacuuming might leave a small amount of oil somewhere in the system, but that's about it. Any moisture will be gone along with any leftover refrigerant. Nobody here can afford to buy a reclamation machine, and yes, if anyone has a charged system that needs repair, I need to put in there that they should go visit a friendly lube or AC shop that will suck up your refrigerant for free. They will reuse it, and charge someone else- so don't let them charge you to remove it.

Yeah, I figured that could be the wrong name for the accumulator. I should've looked it up first, but I wrote all this on the fly. I'm surprised I wasn't corrected sooner. Like Bluefront said, the receiver/dryer/expansion valve system and the accumulator system work much the same way for the shadetree. It's just another spot to change O-rings when the system is down (depressurized). Be thankful we only have O-rings to replace. You want real AC fun, go work on a Chrysler. Not sure about DSM, I avoid Mitsus, and their Chrysler variants like a plague.

Thanks for adding the videos, that will surely help those who can watch the vids.

Bluefront, I have no idea what I'm going to do about 56k users. If I add pictures, then that screws 56k, yet pictures are a great help. I might have to do two, one 56k approved, and one that is full of pics. Not that 56k would never load a thread with pics, but you should at least be forewarned so that you can go get some coffee, popcorn, etc.

There's a lot to these silly AC systems although most people will survive by just knowing how to replace O-rings and recharge. I just recently did my old work van, and showed my business partner how simple it was.

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