Just bought a new 17 wrangler and the a/c blows cold for 6 seconds, then less cold for 6 seconds and then back to cold. And if you move the setting off the coldest blue , it's more pronounced. Anyone else have this issue?
The compressor is supposed to cycle, but with my JK I don't notice a decrease in temperature when it does. If the compressor cycles more than normal the system could be low on refrigerant. It shouldn't happen with a new vehicle, but sometimes there could be a seal issue. Take it in, but unless it starts blowing warm air on the cold setting the dealer will most likely say it's normal. To initially troubleshoot the problem, they should actually check the temperature to see if it's within an acceptable range. It should run approx. 40 degrees below ambient temperature, but it seems like with some JK's that number could be a few degrees higher.
Yes, compressors cycle. My 2017 cycles at about a 5 to 1 ratio (my best guess). In other words, for every 40 seconds its engaged, it dis-engages for about 10 seconds. All these times are approximate. My air never fluctuates in temperature. I have seen faulty thermostats/thermocouples cause what you describe.
Kind of related question on compressor cycling. When I am driving with the AC on I hear the compressor cycle about every 30 seconds, give or take. It seems pretty loud. Just curious if you all can hear your compressor cycling when driving or should it be quiet?
The compressor must cycle to keep from freezing up the evaporator. Chrysler likes to keep the evaporator between 41 and 46 degrees. Earlier JK's cycle the compressor and use a cable driven blend door to set outlet temperature; the blend door determines how much air goes through the heater core or AC evaporator. This is a reliable and simple system.
I must say I don't like the CAN HVAC in 11+ JK's, especially if equipped with auto air. They get very cold and blow a lot of volume, I just don't like the computer control. Unlike the simple cable controlled JK's servo motors are used for blend and mode door control.
Auto air adds additional control of fan speed. The object of auto air is to set a temperature then the electronics will control the target evaporator temperature, fan speed and mode door position. Often the blend door does not follow the EVAP temperature properly so you might get warm-cold cycles from the vents. You shouldn't feel much more than a few degrees change in outlet temperature or there may be a problem.
Starting in 2015 JK's went to R1234yf refrigerant which changes things up a bit too. Have the dealership do a AC performance check hopefully there's an update or other fix.
It sounds as if the system may be a little low on refrigerant.
If you have the AC on try press in on the fan button to turn the air control to recirculate. This mode does not bring in outside air so cools down faster. If it still cycles like that and you feel a difference, definitely have it checked out.
Mine has the same problem except it's a 2015. Mine can only be left on the body and leg setting other wise it gets hot. I got my 35s put on by a dealer here in Hawaii the poor guy was dying from sweat when he had to move it back and forth. Good for him for touching my dials ha
If your A/C does not blow constant cold air when on the upper vents with the fan on high, the A/C dial all the way cold and the recirc option selected (press the fan switch in), then there is something wrong in the control panel and you should take it in.
Now it does take a few minutes to cool it down. But the A/C should be blowing constant cold air until it gets it cool. If I were in a situation where I was in and out of the vehicle like that, I would probably have the A/C off and all the windows down.
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