A/C Auto or On all the time?

Krusty · August 10, 2017

In the Seattle area we are breaking records for heat and 54 straight days now with no rain - go figure...... I have always turned off my A/C before parking.

Does it hurt to just leave your A/C on all the time? Will the condenser mold or something?

Seems like you could turn on the auto to 70 degrees and leave it year round. Unless the rig would not know when to turn on defrosters in cold weather..........

aseibel · August 10, 2017

Interesting question. I also leave it on "auto" in the summer and winter set around 70 degrees. Spring and fall, I probly won't leave it on all the time since I don't need air blowing on me.

I don't think it hurts anything, since the AC turns off when you turn the truck off. after parking, you get that little puddle of water under the front end when the condensation/frost drips off the condenser....

Also, if you have not noticed- when you have it set on "auto" during the winter, it automatically turns the AC on. It is not actually cooling the air, but I think that helps remove moisture from the cabin or something.

Sierra706 · August 10, 2017

Won't hurt your truck. But might hurt johnny c polar bear

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Spurshot · August 10, 2017

Whether or not mold grows on the evaporator is more a question of what's in the air. You guys have so much humidity and vegetation that you have a good possibility of getting something going quickly. Even here in Socal, we get some light smells from something growing. Usually nothing too bad that some Lysol won't cure. Never had to use a foaming cleaner, but I may start doing that once a year.

The "condenser" doesn't get condensation on it, since it's hot as blazes out there in front of the radiator with high pressure and high temperature freon in it. The "evaporator" gets cold. It's in the cab, behind the dash.

Remember, "defrost" is using the AC to dry the air first, then it heats it.

Whether or not mold grows on the evaporator is more a question of what's in the air. You guys have so much humidity and vegetation that you have a good possibility of getting something going quickly. Even here in Socal, we get some light smells from something growing. Usually nothing too bad that some Lysol won't cure. Never had to use a foaming cleaner, but I may start doing that once a year.

Remember, "defrost" is using the AC to dry the air first, then it heats it. So, the same thing is going on.

truckguy82 · August 10, 2017

I just leave it on auto and turn the dial, all year long

Sean Neilan · August 10, 2017

My ac has been on auto literally since the day I bought it in sept 2015. The only times it's off are when I'm driving with the windows down. I keep it at 72 in the summer and 75 in the winter.

Z45 · August 10, 2017

I just leave it on auto and turn the dial, all year long

So do I and been doing that for a long time.

afireinside7444 · August 10, 2017

I keep auto off..... just choose how i want it, dont know why

Spurnedsnot · August 10, 2017

Off till needed

JimCost2014 · August 10, 2017

I believe the "ac" system is always on (when HVAC is turned on) to keep the compressor lubed and the air dry in the truck so you don't have the moisture issues. The AC light does not need to be on for it to be working.

Spurnedsnot · August 10, 2017

Also try to turn it off when I shutdown but sometimes forget

Spurshot · August 10, 2017

I believe the "ac" system is always on (when HVAC is turned on) to keep the compressor lubed and the air dry in the truck so you don't have the moisture issues. The AC light does not need to be on for it to be working.

Hmmm, I'm going out to check that later. I thought my 2014 did not engage the compressor until I pushed the "AC" button. At least I thought I saw that when working on recharging the system.