A/C trick... if anyone wants to confirm?

[alec2538]

Being the constant meddler that I am, and almost never being satisfied with A/C output temp, I decided to see what happened when I removed the evaporator core temp sensor from the HVAC box under the hood and set it aside. My A/C is in perfect working order, fully charged and pressures verified.

Before, cruising down the highway at 60, MAX A/C set to 60, I could get about 41 degrees out of the right hand drivers vent before the compressor kicked off. Didn't matter if it was 75 or 105 out, 40% humidity or 75% (Minnesota SUCKS). Now, 41 degrees isn't exactly warm, but with a system that hold almost 3 pounds of freon and has a condenser the size of most radiators I knew it could do better.

Just for fun, I pulled the evap temp sensor out and placed it off to the side of the box. No, just unplugging it won't work. The HVAC head needs an input or it will cut compressor engagement. Repeated prior tests over a weeks time, and I can now consistently get 31-32 degree air with no rise and fall due to the compressor cycling. I never use the auto temp function, when I want cold I want COLD.

Just for fun: the factory spec on the temp sensor is an "On" temp of 39 degrees and an "Off" temp of 37. This more or less lines up with my initial output temps of 45 degrees "On" and 41 degrees "Off". So my system was working right at the limits of it's designed capacity.

I'm slightly curious if this works for anyone else. I figure you southern owners would especially appreciate this. Apologies if this is old news, also.

[Turbov6Bryan]

I'm curious. Picture of part?

My ac on the DTR has always felt weaker than the black car, if I can get 30 coming out that would be nice

Cool

[mm svt]

That bulb and the canister after it (accumulator/dryer) is to keep liquid freon from getting back to the compressor and preventing damage, without the temp bulb the evaporating core will freezing up from humidity in the air.

[alec2538]

Does this help? It's a two wire connector, pointing straight up. Twist 90 degrees to remove, it's about 4" long. There's plenty of wire to just tuck it somewhere safe, then plug the hole with whatever is convenient. You may need a pliers to break the o-ring seal free after all these years. I did originally, but this year I twisted it by hand.

In the winter, I unplugged the hole and put the sensor back. It probably doesn't matter either way, the only thing the sensor does is report discharge temp to the PCM for compressor clutch control.

Also, for anyone that's worried that this could freeze up the A/C system due to temps dropping too far, there's also a backup low pressure cut off that will kill the compressor if your suction pressure drops and obviously a high pressure cutoff as well. I've had absolutely 0 issues for 2 summers now. It was 92 today with plenty of humidity and she was blowing icicles.

[alec2538]

That bulb and the canister after it (accumulator/dryer) is to keep liquid freon from getting back to the compressor and preventing damage, without the temp bulb the evaporating core will freezing up from humidity in the air.

The accumulator is miles from the evap temp sensor... are you sure we're referring to the same thing? I 100% understand that the temp sensor is there to prevent freezup. Obviously, this is a "do at your own risk" mod, but I've had no ill effects and we have plenty of humidity. Not south Florida high, but high.

[mm svt]

Yes the liquid would still have a chance to evaporate in the tubing on its way.
If you were to close the outlet of the compressor and continue to run the unit the freon charge would mostly be between the orifice tube and compressor in the accumulator, my motor home is capable of doing this and still running R12 from 1985 and that is ice cold.

[tobiasg1995]

I understand you want colder air, and I agree 134a sucks as a refrigerant. Running that low of evap temp will freeze it up, not an if, it will. Plus you cause liquid to slowly start slugging your compressor. Eventually it will scrub the compressor due to lack of oil return. Jmo

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[1Marauder]

More please. Inquiring minds want to know.

[alec2538]

I understand you want colder air, and I agree 134a sucks as a refrigerant. Running that low of evap temp will freeze it up, not an if, it will. Plus you cause liquid to slowly start slugging your compressor. Eventually it will scrub the compressor due to lack of oil return. Jmo

Sent from my LGLS755 using Tapatalk

This is entirely possible. Obviously I don't want anyone to blow up a compressor by doing this. It's free, easy to try, and reversible in 60 seconds if something goes south. That being said, my 206k mile compressor has been working fine for 2 summers this way with no side effects.