$2 Colder A/C mod
#12
JK Jedi Master
The OEM temp sensors installed next to the evaporators have a wide range of resistance values.
Its purpose is to keep the evaporator fins from freezing up.
Assuming the A/C system is properly serviced and operating correctly...
If adding a resistor reduces the temperature of the air being discharged from the vents, while still preventing the evaporator fins from freezing up, the A/C system must still be operating within design parameters.
It can be checked with a thermometer in the center vent opening.
If, after adding a resistor, the temperature is within the limits of the following chart, the system is not being overloaded in any way.
Ambient Temperature........... Air Temperature at Center Panel Outlet
21° C (70° F)........................6 -15° C (42 - 59° F)
27° C (80° F)........................7 -18° C (45 - 64° F)
32° C (90° F)........................9 - 21° C (48 - 69° F)
38° C (100° F)......................11 - 22° C (52 - 72° F)
43° C (110° F)......................13 - 24° C (56 - 75° F)
Let's say it's 110°F outside, and the discharge air temp is 75°F. I then add a resistor to the temp sensor circuit that brings the discharge air temp down to 56°F, and the evaporator fins are not freezing up. I would be very satisfied that I had not done anything to overload the air conditioning system.
Its purpose is to keep the evaporator fins from freezing up.
Assuming the A/C system is properly serviced and operating correctly...
If adding a resistor reduces the temperature of the air being discharged from the vents, while still preventing the evaporator fins from freezing up, the A/C system must still be operating within design parameters.
It can be checked with a thermometer in the center vent opening.
If, after adding a resistor, the temperature is within the limits of the following chart, the system is not being overloaded in any way.
Ambient Temperature........... Air Temperature at Center Panel Outlet
21° C (70° F)........................6 -15° C (42 - 59° F)
27° C (80° F)........................7 -18° C (45 - 64° F)
32° C (90° F)........................9 - 21° C (48 - 69° F)
38° C (100° F)......................11 - 22° C (52 - 72° F)
43° C (110° F)......................13 - 24° C (56 - 75° F)
Let's say it's 110°F outside, and the discharge air temp is 75°F. I then add a resistor to the temp sensor circuit that brings the discharge air temp down to 56°F, and the evaporator fins are not freezing up. I would be very satisfied that I had not done anything to overload the air conditioning system.
Last edited by ronjenx; 08-30-2011 at 07:41 PM.
#13
JK Super Freak
Thread Starter
That is excellent! I will check tomorrow. When I set it up, it was early morning before it had gotten hot outside. I'm going to bring a thermometer to work and check it on my way home when it's 105+
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#14
JK Super Freak
Thread Starter
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#15
JK Enthusiast
Join Date: Nov 2010
Location: saskatchewan
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we consider those cans cocktail mixtures in the industry. Blends of different refrigerants. If you go Into a garage thy will have pure r-134a. Very common refrigerant with multiple uses. it's also in some inhalers FYI. Just need a Cfc to purchase it...I always have a jug on hand for work.
Don't use those cans I have been told not to at least. Pure 134 is the best thing with proper procedure to ensure no non conesnables. Most shops will have an all in one unit. Reclaims the old refrigerant, pulls a vacuum and recharges to factory spec all with the push of a button.
Don't use those cans I have been told not to at least. Pure 134 is the best thing with proper procedure to ensure no non conesnables. Most shops will have an all in one unit. Reclaims the old refrigerant, pulls a vacuum and recharges to factory spec all with the push of a button.
#17
JK Super Freak
Thread Starter
It was 105 today and it was blowing 64 degrees. Well within factory spec. I'm going to continue to measure for a few days.
My friends JK was blowing at 72.
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My friends JK was blowing at 72.
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#18
JK Enthusiast
Join Date: Apr 2009
Location: Albuquerque, NM
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I did this to my jeep a couple of years ago. Works great. I didnt take the dash apart. Just wired it in right at the probe hanging down under the radio.
Lots of people will get scared at things like this saying its bad for your compressor. Yes it will wear your compressor out faster. ANY time you run your compressor it wears it out, and this mod causes your compressor to run more, which means the air gets colder in the cab=good Thing. Nothing more or less. Dont let the compressor freeze up, though. Thats a different thing and that can hurt it.
Lots of people will get scared at things like this saying its bad for your compressor. Yes it will wear your compressor out faster. ANY time you run your compressor it wears it out, and this mod causes your compressor to run more, which means the air gets colder in the cab=good Thing. Nothing more or less. Dont let the compressor freeze up, though. Thats a different thing and that can hurt it.
#19
JK Newbie
Join Date: Jun 2011
Location: Catania, Italy
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I live in north west Florida, and don't see a need for this. But it's all personal preference. I like the concept though. I usually run my ac one a month just to lube the compressor and keep things working. Same with the 4wd. I hardly ever go off road.. But this is my 3rd jeep.