2003 Ford Taurus: A/C Fan not Coming On Time?

AC blower/heater fan is running and starting up.But its not coming up on required time.

You will notice that it comes up when pressure gets too high like 320psi or 350psi or even more then that.

This is most likely a faulty ac dual pressure switch. If it fails, the fan wont come on at proper time and the compressor wont kick off when pressure gets too high, which 350psi is.

As per wiring diagrams if you see:-----
The  fan operation is controlled from the pcm, when the pcm turns the ac clutch relay on it should also turn on the fan relay but isnt. The fan kicks on when high side pressure reaches more then  300psi , and in this condition  compressor  stays engaged as well as pressure then drops and this is not good for compressor.

The pcm gets 2 signals for fan control - one from the ect sensor and one from the dual pressure switch:---
See the wiring diagram shown below for your help:-----




So if the dual pressure switch is acting up the pcm dose not recieve a signal to trun fans on for normal operation.

If dual pressure switch is not working properly, two things happen - head pressure goes up too high as the pressure switch should cut the compressor off when pressure gets too high and fan doesnt cut on when it should to help keep the pressure lower.

And this explains that the signal to the compressor and the fans is not correct due to the dual pressure switch not functioning correctly which is causing the pressure to rise too high and your fan not to turn on until pressure is at 350.

This details will help.

Thanks.

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http://repairhelpcenter.blogspot.in/2012/03/complete-car-repair-help.html

2006 Volvo S40: A/C Runs Intermittently?

Air conditioner is running sometimes for a while then just stops.
In this cases you will notice that A/c stops working but fan just keeps on running.

In this types of problem there is no one single possibility.There are multiple possibilities that can cause this problem.

First thing you have to inspect is compressor.Is the compressor engaging or not engaging when A/c stops running.


there are many possible causes:

-low refrigerant
-faulty compressor
-faulty compressor clutch coil
-faulty pressure switch
-short/open in wiring harness
-internal fault in climate control panel
-fault in ecm
-restriction in the condensor
-restriction in the expansion valve

Unfortunately, as you can see, there is no one single cause. The first step is to read the high and low pressure readings with an ac manifold gage on a test drive to see what the readings are when it quit blowing cold air.

This will let you know or confirm if there is any restriction in either the condensor or expansion valve, if refrigerant is low, or if the compressor disengages.

If compressor disengages, then electrical testing has to be performed to see why and where the signal is lost.

I really wish I could tell you that it is one single thing and you just need to replace "X part", but that is not the case as professional testing is really required for this in order to find the underlying cause out of the several possible causes.



This detail will help.
Thanks.

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http://technoanswers.blogspot.in/2012/03/car-repair-guide.html 

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2000 Chevy Corvette: Vehicle runs hot when A/C is ON?

Engine gets overheated hot in traffic when A/c is turned on.

But in Normal open road it works fine.

In this types of cases the thermostat and cooling fan needs to be monitored.

There are two engine cooling fans on Chevy corvette 2000 year model vehicle.


So first you do need to verify that both fans are properly  working. For that you may need to use a flashlight to see it spinning. If it isnt, then the basics of checking for power to the motor, and if no power, then checking the cooling fan relays and fuse(both labeled) in the engine compartment fuse box.

If no power at the fuses, then engine coolant temperature sensor and ac pressure switches will need to be tested and finally, if needed, the pcm tested.

If the fan is working, then first check for any missing, cracked or broken fan shroud that is allowing for inefficient fan cooling.

If ok, then both ect sensor and ac pressure switch and pcm will need to be monitored with a scan tool to see if the fans are coming on at proper temperature and ac pressure and then fan monitored to see that it is spinning at proper speeds.

I know that sounds like a lot, but with symptoms described, this is in the fan operation in some capacity and will require going thru the above steps to find the underlying cause and then repair.

This details will help.
Thanks.

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Complete Car repair Help FREE? 

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1997 Buick Lesabre: A/C stopped Blowing cold?

On Buick Lesabre 1997 Year model Vehicle it has Automatic Temperature  controls with separate Controls for driver's and passenger side temperature adjustment.

In this case first the A/C stopped blowing cold at passenger side and then stopped blowing at driver side.



Ok, the automatic climate control does not have vacuum controls. The blend doors are electronically controlled by the climate control unit and actuators at the blend doors.

Hence one side stopped working and then the other, this majorly indicates that the climate control module failing rather than both the driver and passenger side blend door.

If the shop doing the work does not have a scan tool that can test the climate control unit and the temperature blend door actuators, you will need to have another shop test it or have a dealer test the system.

This needs to be done before spending money on replacing the doors when it is unlikely that both have failed at once.

This details will help.
Thanks.

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Go to Newly Launched

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http://technoanswers.blogspot.in/2012/03/car-repair-guide.html 

& 
Complete Car repair Help FREE? 

http://repairhelpcenter.blogspot.in/2012/03/complete-car-repair-help.html

What is AC pressure and Temperature sensor ?

If you need dis-assembly or replacement instructions for any other auto/car part, or you want to ask question related to your car/truck jeep problem then please leave the comment with your details, so I can provide you the required instructions and solutions.




A/C Temperature Sensor or Pressure Sensor Operation:An electrical or mechanical sensing device that sends information relative to some physical property such as temperature or pressure to a gauge or light. Also known as sensor unit.


This is how this Sensor looks:---

You can easily buy this part from Autozone service center.

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This details will help.

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Also if you have better understanding of other car AC cooling system parts,then it will help more to troubleshoot the problem.

Check the list below or more help.

Its always advisable to know the AC components working and testing procedure,before replacing any part.

For more details regarding cars AC components.Check out the list of links below:---

How to Perform Car AC Leak detection Test?

http://repairhelpcenter.blogspot.com/2011/11/how-to-perform-car-ac-leak-detection.html

How to Perform AC Pressure Test?

http://repairhelpcenter.blogspot.com/2011/11/how-to-perform-ac-pressure-test.html

How to test Cars AC System?

http://repairhelpcenter.blogspot.com/2011/11/how-to-test-cars-ac-system.html

How to inspect Vehicles A/C Compressor and Clutch?

http://repairhelpcenter.blogspot.com/2011/11/how-to-inspect-vehicles-ac-compressor.html

How to Troubleshoot Vehicles AC Cooling Problem?

http://repairhelpcenter.blogspot.com/2011/11/how-to-troubleshoot-vehicles-ac-cooling.html

How to Replace Vehicles A/C Compressor and Clutch Components?

http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-vehicles-ac-compressor.html

How to inspect Vehicles A/C Condenser?

http://repairhelpcenter.blogspot.com/2011/11/how-to-inspect-vehicles-ac-condenser.html

How to Service Car AC Condenser?

http://repairhelpcenter.blogspot.com/2011/11/how-to-service-car-ac-condenser.html

How to Replace Auto AC Condenser?

http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-auto-ac-condenser.html

How to Replace Vehicles A/C Evaporator Core?

http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-vehicles-ac-evaporator.html

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For car AC related and Heater related solutions. You can refer the options mentioned below:---

Car AC Blows Warm Air ?

http://technoanswers.blogspot.com/2011/10/car-ac-blows-warm-air.html

How to test AUTO AC pressure?

http://howtobyme.blogspot.com/2011/10/how-to-test-auto-ac-pressure.html

AUTO Air Conditioning Troubleshooting?

http://technoanswers.blogspot.com/2011/10/auto-air-conditioning-troubleshooting.html

AUTO A/C COOLING PROBLEM?

http://technoanswers.blogspot.com/2011/10/auto-ac-cooling-problem.html

Fixing refrigerant leak?

http://howtobyme.blogspot.com/2011/10/how-to-fix-refrigerant-leak.html

How to locate Car AC Refrigerant leak?

http://technoanswers.blogspot.com/2011/10/how-to-locate-car-ac-refrigerant-leak.html

CAR AC INTERMITTENT COOLING?

http://technoanswers.blogspot.com/2011/10/car-ac-intermittent-cooling.html

What causes INTERMITTENT COOLING on Car AC system?

http://technoanswers.blogspot.com/2011/10/what-causes-intermittent-cooling-on-car.html

Car AC making Noise?

http://technoanswers.blogspot.com/2011/10/car-ac-making-noise.html

BAD ODOR ON CAR AIR CONDITIONER?

http://technoanswers.blogspot.com/2011/10/bad-odor-on-car-air-conditioner.html

How to Recharge Car's Air Conditioner

http://repairhelpcenter.blogspot.com/2011/10/how-to-recharge-cars-air-conditioner.html

For details regarding:--

How does Vehicles Engine cooling system works?

http://repairhelpcenter.blogspot.com/2011/11/how-does-vehicles-engine-cooling-system.html

Engine cooling components working?

http://repairhelpcenter.blogspot.com/2011/11/engine-cooling-components-working.html

How to flush cars radiator?

http://repairhelpcenter.blogspot.com/2011/11/how-to-flush-cars-radiator.html

How to Service Car AC System?

If you need dis-assembly or replacement instructions for any other auto/car part, or you want to ask question related to your car/truck jeep problem then please leave the comment with your details, so I can provide you the required instructions and solutions.

CAR AC servicing needs proper AC knowledge.Its not a difficult task,but a risky job.

So do it carefully,without any panic.

The procedure is as follows :----

CAUTION
Only EPA-certified technicians can purchase R-12 refrigerant, since proper recovery and recycling techniques are required to prevent damaging the environment. Improper disposal of R-12 refrigerant can result in a fine.

Flushing the System

Flushing must be done with a liquid so grit is carried out. Do not use a vapor (shop air). Using 15 pounds of R-11 refrigerant was the old way that systems were flushed, before the hole in the ozone layer was discovered. Today, mineral spirits are often used for flushing. Mineral spirits are chemically related to mineral oil so they do not present a problem with the refrigerant on R-12 systems. They should not be used on R-134A systems.

Retrofitting an R-12 system

Since CFC refrigerants have been phased out, their cost has skyrocketed. R-134A has been the refrigerant that new vehicles are equipped with since 1994. Look under the hood for a label that states what kind of refrigerant the vehicle has.

Retrofitting an R-12 system is possible, although there are some drawbacks. These are different refrigerants with different properties. Many things must be considered. With the cost of R-12 refrigerant increasing rapidly, do not make the mistake of substituting the wrong refrigerant. R-134A is the only refrigerant any manufacturer is recommending.

Manufacturers have kits that generally go back ten model years for coverage. Follow manufacturers recommendations for retrofitting. Some of the items a retrofit might require are:

• Compressor front seal.
• Some vehicles will require condenser replacement.
• Some will need an extra cooling fan.
• Hoses.

The larger condenser required for an R-134A system is the biggest hardware change. There are many differences between the way R-134A and R-12 react in the air conditioning system:

• 134A has a 30-60 psi increase on the high side and it is 6°-7° warmer.
• The low side pressure with R-134A is typically 3 pounds less than with R-12. This means the pressure sensing switch will probably have to be changed during a retrofit.
• R-134A requires less weight of refrigerant during a refill because R-134A is a different density. At 79°F, R-12 weighs 81.5 pounds per cubic foot and R-134A weighs 75 pounds per cubic foot. That is why an R-134A 30-pound container is larger than an R-12 30-pound container. n R-134A is about 15% less efficient than R-12. That is why the condenser is larger on cars that come equipped with it.

The following guidelines should be followed when converting an older A/C system to R-134a. These guidelines should allow you to provide the customer with a cool vehicle and also meet current legislative mandates. The guidelines are listed in order and reflect the necessary steps for making this conversion.

• Visually inspect all air conditioning and heater system components. Use a refrigerant identifier to make sure the system only contains R-12.
• Check the system for leaks.
• Run a performance test and record the temperature and pressure readings.
• Remove all R-12 from the system with a recycling machine. (Only EPA-certified technicians should work on the refrigerant side of the system).
• If the system uses a compressor with an oil sump, remove the compressor and drain all the oil from it. Measure the amount of oil drained out.
• Remove and inspect the expansion valve or the orifice tube, replace it if necessary. If either is contaminated, flush the condenser.
• Remove the filter/drier or accumulator, drain it and measure the amount of oil in it.
• Before converting, make all necessary system changes, such as hoses, gaskets, and seals.
• Install R-134a compatible oil into the system; put in the same amount you took out.
• Install a new filter/drier or accumulator with the correct desiccant.
• Permanently install conversion fittings using a thread locking chemical.
• Install a high-pressure cutoff switch if the system does not have one.
• Install conversion labels and remove the R-12 label.
• Connect R-134a system evacuation equipment and evacuate for at least thirty minutes.
• Recharge the system to approximately 80% of the original R-12 charge.
• Run a performance check and compare readings with those taken before the conversion.
• Leak check the system.

Also please read this more help links for better understanding.

So this makes you confident,before performing the AC servicing task.

How to Perform Car AC Leak detection Test?

http://repairhelpcenter.blogspot.com/2011/11/how-to-perform-car-ac-leak-detection.html

How to Perform AC Pressure Test?

http://repairhelpcenter.blogspot.com/2011/11/how-to-perform-ac-pressure-test.html

How to test Cars AC System?

http://repairhelpcenter.blogspot.com/2011/11/how-to-test-cars-ac-system.html

How to inspect Vehicles A/C Compressor and Clutch?

http://repairhelpcenter.blogspot.com/2011/11/how-to-inspect-vehicles-ac-compressor.html

How to Troubleshoot Vehicles AC Cooling Problem?

http://repairhelpcenter.blogspot.com/2011/11/how-to-troubleshoot-vehicles-ac-cooling.html

This details will help.

Thanks.