- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
It is very possible that the A/C is not engaging part of the time. It can be overcharged. You have 2 safety switches on the A/C system. A high pressure and a Low pressure.
Pressure inside the system is dependent on the background temperature where the car sits. This means the A/C does not have to be turned on for the switches to activate. Their job is to cut off power to the compressor, so when you start your car, the power to the compressor may already be switched off.
There are charts for filling the Freon system. For sake of conversation, lets' say the low pressure cuts off at 20psi and the high at 300psi. Those are the ratings for the respective switches. You have a low charge, say 25psi at 80 degrees outside temp. Overnight or a Cold front comes in and the outside temp is 70 degrees. The system drops to 19psi as the car sits. The compressor clutch will not get power. Also for the high switch, the car sits as outside temp goes to 100 degrees. The A/C pressure climbs to 325psi as the Freon expands, the compressor clutch will not get power.
This is why many instructions tell you to bypass the pressure switches to charge the system. Your switches are constantly working to keep the pressure between 30psi and 300psi. MODERATION is key here. The longer the compressor clutch stays engaged, the more cooling you will have.
So the car makers recommend a fixed amount of Freon for each Model of car. Volume capacity is different for the length of the hoses, the size of the condenser, the chamber inside the compressor. It all is calculated so they know how many LBs of Freon will fit in the space to produce a given pressure.
Most of the pressure switches can be changed without significant loss of Freon, just a puff when the switch is removed and replaced. I have replaced more low pressure switches than the highpressure. It is probably because the springs are much weaker on the low side.
Some major autoparts stores have tool loaner programs. Manifold gauges are used to read both pressure ranges. If you did not purge the system with an electric or air powered Vacuum pump, you may have water condensation forming ice in the lines.
best diagnostic method is dual head gauges. balanced pressure between low and high side in the off position is aroung 90 lbs. running low pressure is 20-40 lbs and high pressure 160-200, is the compressior not coming on? does it stay on, or click on and off. either might mean the freon level is low. try unplugging the low pressure switch on the low side supply line and shorting the pigtail wires together with a paper clip. does the compressor stay on now? if so and the air is warm or cool, freon is low. if the air is cold that switch is bad. if compressor still won't come on the list of possibilities grows longer: compressor, comp fan clutch, AC relay, restriction at several places... repair shop time...
80lbs on the low side is WAY too much if the clutch is running, the high side you should see 125-150ish, the low 30-40. I would feel the lines (the bigger line going into the firewall to see if it is cold when your pressure is right) if so suspect a blend door motor which controls the hot and cold switching inside.
I have the same car. The cooling fan activates at 227F. Only one fan will engage at this temp, the other one[closer to the A/C compressor] won't engage unless the A/C is working. Try charging the system with half a can of refrig. It'll be tough retrofitting to R-134A, the LOW PRESSURE connector is under the air box pointing sideways about an inch from a large bracket. Try and find a 90 degree adapter of some type and go from there.
The cooling fan does not come on until the engine temp reaches 229 degrees. it is controlled by a cooling fan relay. Cheeck for power at the fan motor and check the relay. The A/C. If yuor a/c system is low on freon the low pressure switch on the accumulator will not complete the circuit for the clutch. Check the charge, voltage present at the clutch or the low pressure switch. You can install a jumper in place of the switch to test.
the tracer is the same as the ESCORT, right?? TRY THIS--I WORK ON PLENTY OF ESCORTS--LOOK UNDER THE AIR CLEANER/CONE ASSEMBLY--THERE WILL BE A BLACK METAL BOX(FULL OF RELAYS) ONE OF WHICH IS THE A/C RELAY--TRY TAPPING ON IT WITH A LONG SCREWDRIVER OR SOMETHING SIMILAR WHILE U HAVE THE A/C ON. IF THE A/C SUDDENLY STARTS WORKING U NEED TO GET A NEW RELAY BOX(I THINK ITS CALLED A GEM MODULE) i do have a question- does the blower motor work?? how do u know the compressor is good??do you have 12 volts going to it??? this relay box is pretty common to go bad--u have to remove the air cleaner in order to get to it.get back to me.
These numbers are a little high depsite the high ambient conditions.Amazingly enough ,automotive low side suction pressure will equal the degrees its putting out at the evaporator coil...for instance,70 psi low side pressure will produce about 70 degrees of cooling. At 300 psi on the high side(which is high) this is about as low as the suction pressure will go....you need it to go lower.I would probably be concerned with the freon level as a slight overcharge could boost these numbers.Poor air flow through the condenser can also create a higher head pressure than desired.If possible,I would evacuate and re-charge the system with the correct amount of 134a refrigerant. Try to get those pressures lower...about 250/50 would be a decent pressure value in this ambient condition.Verify good airflow through the coils and pay close attention to any foreign debris like plastic grocery bags or wrappers covering the coils...Ive even seen these make their way between the small gap between the condenser and radiator so use a light and inspect carefully for this.Air flow through that condenser coil is vital and any deficit there will create high head pressure which obviously causes high suction pressures....good luck