sounds like the air-conditioning expansion valve is probably not working correctly here is a way you can fix your air conditioning:
Realize that auto AC is basically a refrigerator in a weird layout. It's designed to move heat from one place (the inside of your car) to some other place (the outdoors). While a complete discussion of every specific model and component is well outside the scope of this article, this should give you a start on figuring out what the problem might be and either fixing it yourself or talking intelligently to someone you can pay to fix it.
Become familiar with the major components to auto air conditioning:
the compressor, which compresses and circulates the refrigerant in the system
the refrigerant, (on modern cars, usually a substance called R-134a older cars have r-12 freon which is becoming increasingly more expensive and hard to find, and also requires a license to handle) which carries the heat
the condenser, which changes the phase of the refrigerant and expels heat removed from the car
the expansion valve (or orifice tube in some vehicles), which is somewhat of a nozzle and functions to similtaneously drop the pressure of the refrigerant liquid, meter its flow, and atomize it
the evaporator, which transfers heat to the refrigerant from the air blown across it, cooling your car
the receiver/dryer, which functions as a filter for the refrigerant/oil, removing moisture and other contaminants
Understand the air conditioning process: The compressor puts the refrigerant under pressure and sends it to the condensing coils. In your car, these coils are generally in front of the radiator. Compressing a gas makes it quite hot. In the condenser, this added heat and the heat the refrigerant picked up in the evaporator is expelled to the air flowing across it from outside the car. When the refrigerant is cooled to its saturation temperature, it will change phase from a gas back into a liquid (this gives off a bundle of heat known as the "latent heat of vaporization"). The liquid then passes through the expansion valve to the evaporator, the coils inside of your car, where it loses pressure that was added to it in the compressor. This causes some of the liquid to change to a low-pressure gas as it cools the remaining liquid. This two-phase mixture enters the evaporator, and the liquid portion of the refrigerant absorbs the heat from the air across the coil and evaporates. Your car's blower circulates air across the cold evaporator and into the interior. The refrigerant goes back through the cycle again and again.
Check to see if all the R-134a leaks out (meaning there's nothing in the loop to carry away heat). Leaks are easy to spot but not easy to fix without pulling things apart. Most auto-supply stores carry a fluorescent dye that can be added to the system to check for leaks, and it will have instructions for use on the can. If there's a bad enough leak, the system will have no pressure in it at all. Find one of the valve-stem-looking things and CAREFULLY (eye protection recommended) poke a pen in there to try to valve off pressure, and if there IS none, that's the problem.
Make sure the compressor is turning. Start the car, turn on the AC and look under the hood. The AC compressor is generally a pumplike thing off to one side with large rubber and steel hoses going to it. It will not have a filler cap on it, but will often have one or two things that look like the valve stems on a bike tire. The pulley on the front of the compressor exists as an outer pulley and an inner hub which turns when an electric clutch is engaged. If the AC is on and the blower is on, but the center of the pulley is not turning, then the compressor's clutch is not engaging. This could be a bad fuse, a wiring problem, a broken AC switch in your dash, or the system could be low on refrigerant (most systems have a low-pressure safety cutout that will disable the compressor if there isn't enough refrigerant in the system).
Look for other things that can go wrong: bad switches, bad fuses, broken wires, broken fan belt (preventing the pump from turning), or seal failure inside the compressor.
Feel for any cooling at all. If the system cools, but not much, it could just be low pressure, and you can top up the refrigerant. Most auto-supply stores will have a kit to refill a system, and it will come with instructions. Do not overfill! Adding more than the recommended amount of refrigerant will NOT improve performance but actually will decrease performance. In fact, the more expensive automated equipment found at nicer shops actually monitors cooling performance real-time as it adds refrigerant, and when the performance begins to decrease it removes refrigerant until the performance peaks again.
Taurus does not use a heater control valve. It runs coolant thru the
heater core constantly. You may have a temp blend door actuator problem
or a plugged up heater core is also very common. Feel the heater hoses,
they should both be very hot, it one is much cooler; you can try to
back flush the core.
My name is Ron,and I have one solution,Sounds like you need some freon added,if that doesn`t fix ya ,the ac compressor could be weak,or blockage in ac system,or vent door not opening,or opening slowly,and not all the way...hope this helps,[email protected]
Your problem is a faulty heater control valve. The design used on these vehicles allows for hot water to flow constantly and compete with the evaporator as there is no blender door. You have to replace the valve and possibly the control head. Meanwhile, you can bypass the valve to have cold air
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If it works sometimes but not others, the most common faults are overheating components (AC clutch, control relays, ) pressure problems (high or low pressure or sensors reading too high or low after they are on for awhile), or defective blend door or temp control system.
AC isnt complicated. It really hasnt changed much at all in 20 years, and didnt change for 50 years before that aside from what refrigerant is put in. the theory hasnt changed. If you mechanic was checking condensers for leaks, and didnt find them, Id suggest someone more skilled at AC work. Condensers are NEVER EVER intermittent problems. They leak, or they plug solid. Neither condition comes and goes. Your problem is in system pressures, or electrical control, or clutch. Period.
Sounds like you may have water in the system. If that they case you'll need to have the system evacuated and refilled by a professional. It'll probably need to have the dryer cartridge replaced as well.
You say that i holds a charge, and the compressore turns, but does the comprressor cycle on and off, as this is indicating that there is enough charge, and once there is low pressure detected, it turns the compressor on, and when it reaches a high pressure, the compressor cycles off.
Lastly, when engine running and AC on, if you feel the 2 pipes going in to the firewall, one should be hot, the other should be cold ???...is this happening ???
you should check if there is gas on the air system, if you say the compressor its engaged all time perhaps you have a gas leak or too much low pressure on the gas system, its recomended that this work is done by a pro, as it involves hazardous gases and delicate procedures.
Is the compressor engaging? If not he needs to find if a sensor issue if its fully charged or a low pressure or refrigerant condition. You can have pressure without refrigerant.
I think you could be right about there being air trapped in the system. Or the heater core(radiator) is plugged. Either way you need a pressurized radiator coolant pump to put the coolant in without air being trapped. Although,i have seen it done by jacking the vehicle up high enough that the radiator was now higher than the heater core level, and then the coolant was put in. But this is dangerous to try.
HI, giving the compressor 12v directly is not the way to go as you are bypassing the entire fail safe cercuit. it seem to me that your ac gas is low(can be checked via ac pressure gauges) wich means you have a system leak sumwhere. as soon as your hi/low pressure switch(depending on system) detect inferior pressure to the spesified pressure ,the ac compressor voltage is cut in order to protect the pump from seizure.
Or perhaps your evaporator(small radiator like unit behind dash) can get freezed up caused by either too mutch system gas(check pressure) or poor opperation of the expantion valve. the evaporator then has a sensor(themometer) wich measures evap. temp and if the value drops below spec (usially round about7degrees) the ac compressor will be cut once again(fail safe)
Maybe your ac compressor overheats due to inferior system oil/oil capasity, also note that only some systems incorperate the function of measuring ac pump temp. then again temp to high= fail safe=no12v to ac pump.
Id say you have to go into it and see. Sounds like the compressor is
not running. The small copper pipe should be warm and the big copper
pipe cold and wet. Could be anything low pressure switch ,wire off, cap
gone???????
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