1992 Chrysler Jeep Cherokee: A/C System Pressure is Same on Both High and Low?

In this condition the A.C cooling problem will be noticed.


The 1992 year Chrysler Jeep came with R12 from the factory.if Your jeep is using R134A, then it was converted.


It wasnt until late 1994-early 1995 that R134a became available.

the system calls for 38 ounces, but with R134A conversion, less is installed due to molecule differences in the refrigerant. The industry rule of thumb is 80% of called for. So for yours that will be 30ounces.

Ok, pressure should be 28-35psi on low side and 175-220psi on high side. If it were a restriction in the expansion valve, pressure would be high on the low side, but near normal on the high side.

Yours is neither sucking on the low side, nor pumping on the high side, hence the high low side pressure, and low high side pressure.

If you are positive of the system being at the correct level and compressor engaging, then only one thing causes this - weak compressor. It needs to be replaced.

So the compressor needs to be inspected and tested before getting replaced.

As per description it says compressor is faulty.

This will help.
Thanks.

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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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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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How to Perform AC Pressure Test?

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.

The AC pressure testing is As follows :----

Pressure Testing

A pressure gauge set is used to measure pressures in the system. One of the gauges is for high side pressure and the other is for low side pressure.

A pressure gauge set is used to measure pressures in the system. Courtesy of Ford Motor Company.

The gauges and hoses are of a standard color code:

• Red is the high side.
• Blue is the low side.
• Yellow is for charging and discharging equipment.

This is the same color code that plumbing follows for hot and cold water. The gauges are connected to one manifold with another hose fitting for performing service procedures. Evacuation and recharging of the system can be done through this port.

Before connecting the gauges to the service ports, close the manifold hand valves and any valves on the service hoses at a refrigerant tank or vacuum pump. Be careful that the hoses do not hang in the fan or on an exhaust manifold. Then, connect the gauges.

Connect the gauges to the service ports. Courtesy of Ford Motor Company.

The low pressure gauge is a compound gauge. It reads in either low pressure or vacuum. This is because it is in the suction side of the system. There is a hand-operated valve that opens and closes the suction line to the service hose used to charge the system. The gauge is always open to the suction line and registers that side's pressure.

The high side gauge registers pressure only. The gauge usually reads to 500 psi. Most high side gauges have a small orifice in the inlet. This keeps the needle from fluctuating rapidly as the system pulses. Many gauges have a zero calibration adjustment screw on the gauge face also. Sometimes gauges have a scale to convert pressure readings to relative temperature.

The hand control valve for the high side opens and closes the line to the high pressure service hose, used for discharging the system. The gauge always measures pressure in the high pressure side.

With manual service valves, use a special wrench to mid-seat the valve by turning the stem one or two turns. It must be back-seated before removing the hoses. Modern service hoses have a check valve in the end of the line to prevent refrigerant from escaping when the line is disconnected. A small amount can still get out. When removing a hose from a connection, put a shop rag around it to prevent oil and refrigerant from spraying. Disconnecting the low side while the system is running results in the lowest pressure at that connection.

The pressure reading in the system when it is not operating is called the static pressure. This will be at least 50 psi if there is enough refrigerant in the system. High and low side pressures will be equal when there is no movement through the system.

When you start the engine and turn on the AC system, the low side pressure will drop and the high side will increase. Pressure on the low side will change according to the temperature in the evaporator. The high side will reflect the temperature of the liquid refrigerant leaving the condenser. The pressures will continue to change until the system stabilizes (reaches its normal operating temperature). The system pressures are stabilized when maximum high side pressure when the system cycles off does not change from cycle to cycle.

The pressures will vary with humidity because high humidity puts a higher load on the system. Adequate air flow over the condenser is also required. A portable fan might be necessary to blow additional air through the grill on a car with a belt driven fan. Expected low side pressures differ between expansion valve and orifice tube systems. Troubleshooting charts in manufacturers' service manuals will help pinpoint the causes of pressure problems. The following are rules of thumb for the pressure test:

• The higher the high side pressure, the more heat there is.
• The lower the low side pressure is, the lower the temperature will be at the outlet.
• High side pressure affects low side. When you squirt water on the condenser, the high and low pressures both drop at once.

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This details will help you.

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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

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

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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