2001 Ford Escape A/C Problem

[keiken01]

My sons A/C keeps cycling off an on. I put a gauge on the low side ( cheap ones that come with freon kit at walmart) and it shows the pressure building from low freon to good then borderline to high and then it shuts off. Is this an indicator the system is overcharged?


2007 Ford Focus A/C Problem

My daughters A/C keeps cycling off an on. I put a gauge on the low side ( cheap ones that come with freon kit at walmart) and it shows the pressure building starting out as high freon then goes off. Is this an indicator the system is overcharged? She just bought the car used last week and it was working just fine, so I know she hasn't added any freon.

Oh and just a side comment... What the heck was FORD thinking to locate the low side connection behind the wheel well of the passenger front wheel? This makes charging a complete pain in the @$$.

[Daniel Wood]

keiken, it's identical questions that you need answers to is the reason why I moved it.


At any rate, I hope ya get your problems solved.

[thcardoc]

The Escape. That is not enough information to judge the charge in the system, nor all of the systems operational characteristics. Starting out low, and then seeing the pressure increase suggests that the system is picking up heat, but it isn't able to get rid of it. Notice that I use the word suggests looking at the low side pressure and nothing else is like walking up to a microscope and looking at the specimen without any other information about what it is or why it was even put there for examination. That's the problem with the DIY kits that suggest you can repair your AC system yourself and suddenly do everything that a pro does. Do you want to know what's worse than that? AC system sealants do work to a degree, but they also render the system dangerous to a shops recovery/recycling equipment and nullify any warranties from the manufacturers of replacement parts.

For the Escapes system to pick up heat, but not be able to get rid of it at least while your testing the system while the car is sitting I'd be suspect of the cooling fans operation, and/or the airflow through the condensor and radiator. I need to see the high side pressures and then manipulate the airflow through the condensor and see if I can influence any change in order to prove what is occurring. The system "could" be low on charge, AND also have a high side airflow issue. I'd also need to take a sample of the refrigerant and run it through my identifier to see if it is contaminated by air, HC's or other refrigerants (R22, R501 etc)

The Focus. Starting out "high" on the low pressure side when first turned on, and then seeing it go low as the compressor pushes refrigerant to the high side of the system is exactly what you should see occur. If the system is undercharged, the refrigerant won't get sufficiently pressurized to cause it to turn into a liquid state inside the condenser. Now just because she didn't add any refrigerant that it doesn't mean that someone else didn't right before she bought the car. You see advertising everywhere that tries to tell people that they only need to add refrigerant and that's all it takes to make the car's AC system work. The problem is if the system is low it has a leak, but where is it and how big is it? We use a combination of methods to locate leaks, from electronic "sniffers" to dye's detectable under a black light.

The location of the test port. It is in an annoying location but to help make system testing more reliable it must be close to the accumulator, or on the accumulator itself. There simply isn't much room for the accumulator under the hood and since it had to go somewhere.....

They don't worry much about what it takes to service/repair cars. But with the correct equipment, it's not a big deal to service that system.

[keiken01]

Clarification... On the Focus, the pressure does not drop it starts high and stays high until the compressor shuts off... so from the walmart gauge, it starts out red and stays red... and since it used to work when she bought the car, I was thinking that maybe this meant a bad compressor.

I do have a set of refrigeration gauges, but it has been so long since I did anything with them I don't remember much except how to connect them and stare with a glazed look that they both have a reading.

I will connect them to each system and let you know what I see.

[thcardoc]

Starts out red and stays red. This is the same tool that was attached to the Escape, right? Any chance that it didn't really connect to the system and was simply displaying the pressure trapped in the gage from the charge can?

[keiken01]

From the walmart gauge ...
The Escape starts out green and climbs to high blue (good) then shuts off at ~45 psi.
The Focus starts out red and stays red like ~145 psi. These gauges allow for connection without a can and I even removed it to clear the line and put it back on just to be sure it was correct.

I'm getting ready to remove the wheel and try both with A/C pro type gauges on high & low and will report back.

[keiken01]

Escape - High side starts at 100 drops to 80 kicks off while low side starts at 22 climbs to 45 kicks off. I know my son added freon last fall along with a sealer and went off to college with everything working and he said he has done nothing else to it. This makes me think it may just be low, with it climbing to 45 then stopping makes me think maybe the sealer could have caused other problems... he said he next to never used A/C since October because he was in northern CO, but is now back in MO where humidity is a tad higher ;-).

Focus - high side starts at 150 does not change to kick off while low side/receiver starts at 150 drops to ~70 kicks off. Only history I know is that it was working and now its not and no one has done anything to it.... I let the car run for about 20 minutes and it overheated. Going to check fuses now...

[thcardoc]

Originally Posted by keiken01

Escape - High side starts at 100 drops to 80 kicks off while low side starts at 22 climbs to 45 kicks off. I know my son added freon last fall along with a sealer and went off to college with everything working and he said he has done nothing else to it.

As the compressor pumps the refrigerant from the low side, to the high side, what you should be seeing is the compressor turning on, the high side going from 80 psi to 100 psi while the low side goes from 45 psi and drops down to 22 psi when the compressor turns off. That's an undercharged system.

Focus - high side starts at 150 does not change to kick off while low side/receiver starts at 150 drops to ~70 kicks off. Only history I know is that it was working and now its not and no one has done anything to it.

Starting out at 150 psi is troubling. The static refrigerant pressure will reflect the ambient temperature if the vehicle is allowed to sit and cool off. Picking up underhood heat would push that upwards and could give the numbers you are reporting, but contaminated refrigerant could do that as well. From there the system should have stayed on and dropped the low side pressure into the mid thirties to high twenties depending on engine speed, airflow through the condensor, ambient temperature and humidity. Your system shut off too soon, so testing of the compressor clutch control inputs and computer commands are in order. This is best done by starting your next step with a fully functional scan tool, and a schematic for the compressor clutch control and command circuits.

[keiken01]

FOCUS - Ok, so I checked and a fuse had blown for the fans... ran to the store, got a new fuse in and everything is working fine. This was a surprise and really feel like a dolt now. I had driven the car the past couple of days putting over 100 miles on and never got close to overheating... obviously this was an airflow problem.

ESCAPE - I told my son it needed charged and he said he didn't use the a/c so I'm going to see how long that lasts.

Thanks for your help. The earlier comment about airflow got me the idea to keep the car running to see if the fan ever kicked on.