The A/C on my 2012 Escape keeps freezing up. Happens mostly on highway and humid days. It's been to the dealership and had literally everything except the hoses/lines replaced.

The final paperwork from Ford said to run it only on the recirculate setting when running the a/c. This helps but I really would prefer the fresh air setting.

Anyone else have this problem? I feel there is a problem with the system but maybe it's a design flaw instead of an equipment malfunction?

I live in Central VA. Humid and warm.

 

The pressure switch for the low side should cycle the compressor OFF before the evaporator condensation freezes.

 

Justanother ignorant technician & service writer. Ski is correct. There is an LPCO, low pressure cutoff switch that will/should disable power to the compressor clutch when the pressure in the evaporator drops below the boiling point of the refrigerant ~freezing[water]. The compressor can remove so much refrigerant the pressure drops, causing the refrigerant to boil at very low temperature, thus causing frost on the evaporator coils. The LPCO is designed to prevent the pressure from dropping{thus the boiling point} significantly below the freezing point of water. It can be adjusted using a flat blade screwdriver between the two prongs of the connector. It can also be replaced without evacuation and recharge of the refrigerant. [As can schrader valve inserts]
tom

 

Hi Tiggie,

Let's see what I can do to keep your A/C from turning into a popsicle. How many miles are on your Escape?

Crystal

 

Interesting. I have adjusted the low side cut off on another one of my cars when I converted from r12 to 134a. Forgot about that but certainly worth a try.

It is a 2012 with 42k. Is a CPO - the 1-year bumper to bumper expires this weekend.

Attached is a pic of the last service paperwork. Sorry it's crooked.

 

Same pic right side up so you don't have to read sideways!

 

If the system has an expansion valve [TXV], then it should not freeze up unless the valve sensor does not have good contact with the evaporator or the valve is adjusted slightly too 'low' in the cutoff direction. A TXV has a sensor bulb that is to be smushed against the evaporator to sense the temperature of the evaporator itself. The TXV is supposed to meter the refrigerant such that there is always just enough to keep the evaporator chilled to right near freezing. I do NOT know if it is run much under 32F or is kept just above. I think they are set just below freezing, such that a thin sheen of frost will/can form, the barest layer. That should maximize cooling. If so, and you run into heavy humidity, you can get thicker frost formation, especially if you do not run the blower at a high speed, thus working the evaporator a little harder.
With frost formation and the refrigerant at proper level, you get max efficiency when you can frost up your evaporator, but don't.
I'd run it in re-circ, and figure that the system would become a bit less efficient over time, and I'd be ahead of the game then. Some models of TXV can be adjusted, some are fixed. I dunno what FoMoCo uses, but it is likely not worth the hassle to figure that out.
I do not know if the dealer checked the LPCO to make sure it is not pulling the pressure so low before compressor cutout. If the LPCO were set too low, it could contribute to frost formation in that the TXV is sending all the refrigerant it can... but it is not enough to keep the evaporator from freezing up. I would want to know the LPCO cutoff pressure and the high side pressure, to insure that the compressor is not starving for refrigerant on the suction side and is receiving adequate lube. I am not a reefer mech.
tom

 

Is "smushed" a technical term?

I've read in some very hot climates they use a bypass switch mounted in the cab to get the coldest air possible and the evaporator almost frozen.

 

It does have an expansion valve judging by the service paperwork (they replaced it).

So I suppose I will need hook up the gauges to see exactly when the low side cut off is activating. Then figure out whether to adjust the LPCO or expansion valve (if possible).

Years ago, I had this same problem with a 1982 Ford LTD. After extended highway trips, the compressor would run constantly (no cycling). The Escape does this same thing - the compressor runs constantly (never cycles off) after I see ice on the evaporator lines. Maybe it is the same cause. What would cause the LPCO to become non-functional?

I'll also mention that on the Escape, after freezing up, it starts blowing fog out of the vents.

 

Thanks for replying, Tiggie. If you'd like, I can get this escalated to the customer service manager for your region. To make that happen, PM me your full name, best daytime phone number, VIN, current mileage, and servicing dealership; I'll do the rest.

Crystal

 

tiggie, the LPCO is not functional if the compressor clutch is engaged when the evaporator is iced up. A small amount of frost is reasonable, such that it would melt in a few seconds if the compressor were de-powered. Iced up? Nope. Something wrong, likely LPCO or LPCO setting. I suppose the LPCO internals could get jammed, gooey, or have welded points.
tom