Honda AC

Factual Questions
1

I drive a 2001 Honda Civic LX. It’s green. My question is about the air and the air conditioning.

When I turn the dial to Defog/Defrost, the light on the AC button goes on. When I’ve had enough of Defog/Defrost, and decide to have just plain air (neither heated nor cooled) blowing from the vents, I turn it back to Plain Air and turn the heat all the way down. Except that the AC remains on. Since I tend to use Defog/Defrost only for heat when the temperature is chilly, I sure don’t appreciate being hit with cold AC if I forget to switch off the AC which has remained on without my volition.

Questions:
1.Why did they rig it that way? Why make you go through another step to shut off AC if you didn’t want it on in the first place?

  1. Is there any way to disable this bug? (“Bug”? You can tell I’m more used to working on computers than on cars.)

Apart from that problem, I like the Honda Civic as a good all-round reliable transportation vehicle.

2

Personally, I like it better the way you described. It gives you more control.

Are you used to domestic cars? Most Japanese cars are like that.

3

I don’t see how it “gives you more control,” since all it does is needlessly make you perform an extra action. I mean, heating and AC are antithetical and I cannot conceive of needing to use them both at the same time. It makes no sense to me.

As for domestic cars—HA!! My other car is a 2000 Chrysler Voyager minivan, and you cannot shut off the flow of air from the outside when you have the Defog/Defrost on. When you desperately need the Defog for visibility, and at the same time you are stuck behind a truck belching noxious asphyxiating exhaust, you curse the idiotic design, capisci? Who comes up with these brilliant ideas?

4

Because the AC also removes moisture from the air in the passenger compartment, thus preventing the windows from fogging.

I’m sure it was designed that way, so it’s not a bug.

By the way, I drive a 2001 Honda Civic LX. Green.

5

They tried to help you and make it smarter, but they didn’t quite make it smart enough. As oliversarmy mentioned turning on the AC removes moisture from the air which makes the defrost work better. I didn’t really believe how much until I was in a car in the winter and the window fogged up and the person in the passenger’s seat told me to turn on the defroster and press the AC button. I reminded him that it was winter and I didn’t feel like growing icicles from the roof, to which he replied turn the temperature to hot and press the AC button. I skeptically pushed the button and watched as the window very rapidly defrosted. So, someone at Honda was really smart and decided to do this automatically for you.

The problem is that you car’s memory is worse than a goldfish (which is 3 seconds if I am to believe a trivia answer). Once it’s in defrost it doesn’t know where it was before, so when you switch it back to plain air it doesn’t know whether or not you had the AC on or not before, so it leaves it on.

In computer speak, it’s not a bug it’s a feature. :smiley:

Until they equip your car with a “back” button I don’t see any easy way out of it. Personally I’d rather have the thing not muck with my AC at all but unless you are going to hack your car’s computer that’s probably not an option.

Please tell me it’s not that new ugly puke green color I keep seeing all over town.

6

It gives you more control mainly for the reason Oliversarmy said. I use heat and a/c all the time to defog my windows. Not to mention the fact that this is sometimes a lifesaver (or car-saver) if your car is overheating due to a bad coolant fan.

Also, it gives you the ability to turn on the A/C regardless of whether the vent is open or closed, and regardless of which output you have selected. That’s more control.

I know exactly what you mean about the controls on your Chrysler, which is one of the reasons I hate the controls typically found on domestic cars.

7

I missed the control style off my Civics when I got back into domestic cars. There was no way to turn on the A/C and direct the air to the vent I wanted. The Hondas both had a separate switch for the compressor for any setting I wanted. Note: my 1990 Si and 1995 EX did not automatically turn on the compressor ever. That was a good feature – leave the operator in control.

I question, though, why being able to turn on your A/C would help with overheating? The compressor makes the engine run harder (=hotter!).

My last two domestic cars (one GM product, one Ford product, not counting the Ranger) were even better than the Honda, though. Sure, the Ranger still suffered from the “lack of control,” but nothing beats climate control. Unless I want to run the defroster (which automatically engages the compressor), I’ve never had to mess with the temperature controls a bit. They stay perfect all year long. Soooo… we can’t say all domestic cars suck (yeah, I see your word “typically” :slight_smile: ).

8

I drive a Green 1999 Honda Civic!
I remember when buying it having a little q-card type explanation of this in the little compartment under the radio. It said that if you put the defrost option, the AC will automatically come on. I was not too happy thinking I did not want to freeze my butt off each time I defrost the window, but if you put heat on as well, you still get the heat towards you and the AC is only against the windshield. You do have to manually push the AC button to shut it off, it does stay on…

OK, just going back and reading Engineer Comp Geek said the exact same thing but way clearer…
Heck, I’ll post anyway!

9

It’s a works better to engage the compressor when you are trying to defrost the car, I think we all agree on that.

They are trying to make the car smarter and forgot a step. Have you checked service bullitens to see if there is one for this (or call the dealer)?

My sister’s Cavalier works as you describe except it remembers if you had the AC off when you take it back of of defrost.

I hope someone comes along soon to elighten me about voltaire’s comment on using the AC to help a car with a broken coolant fan. I understand using the heat, but the AC is a new one on me.

10

I should add that my comment about voltaire’s post doesn’t exclude voltaire from responding, it was a miswording.

11

Honda’s are designed to activate the A/C when you switch to the defrost/defog mode, because they require the extra-dry air (as previously mentioned). Honda’s typically have far more glass than other cars because of the low belt-line (windows that go lower) design that they typically have. Blowing even slightly moist air directly at such large windows will nearly instantly fog them if the A/C is not turned on.

12

Reading that now, I realize I probably should have explained that better. I kind of just threw that bit out there. Sorry.

Most (almost all) modern cars with A/C have two fans behind the radiator. One, the coolant fan, turns on according to the coolant temperature. The other, the A/C fan, only turns on when you turn on the A/C and the compressor is engaged. Both are to help draw air away from the radiator in order to cool it and the engine.

If you happen to have a bad coolant fan, (which I currently do) and it never turns on, turning on the A/C makes up for it by turning on the other fan. If you’re constantly moving at a good speed, like on a highway, you don’t really need the fans much. But if your in heavy, slow, stop & go traffic and you have no fans turning, it is very likely that your car will overheat. Leaving the A/C on will usually help prevent this. In this situation, the added load of the compressor is totally offset by the fact that the car is idling away anyway.

Now about the heat bit… If you get to the point of overheating, regardless of the cause, it is always good to turn on the heat in your car and open up all the windows. This helps draw a lot more heat away from the engine, through the vents and out the windows. If you ever get to the point where you turn on your heat, but there’s no hot air coming out, then it’s time to pull over and let the car cool while you go get some water.

Unless you’re on the highway, where it is much less necessary, turning on the A/C along with the heat (preferably with fresh, not recycled air) is the best thing to do to prevent or at least slow overheating.

I’ve had people call me crazy when I’ve told them to turn on the heat when their car’s overheating. At first, it doesn’t sound like it makes sense. But a car’s heater doesn’t “make” heat when you turn it on, it uses the heat in the coolant that the engine already made.

13

Oh, BTW, the water is for the car, not for you. :slight_smile:

If you turn on the heat and no hot air comes out when the engine is already warmed up, it most likely means the car has low or no coolant.

14

Thanks to everyone who explained, I understand now better. Cerowyn’s explanation being the clearest and most concise.

Certainly not, it’s a suave dark green, what d’ya call it, forest green. I have not seen what you describe. I chose the 2001 Honda Civic to be my new car when looking through comparative ratings in the AAA magazine, and it looked the best overall. My daughter asked me what color I preferred, and I said “green.” Then she informed me she’d heard somewhere that green was the color preferred by geniuses. :slight_smile: (I don’t know any cite for that.)

15

Green is also the color preferred to calm mentally ill patients, according to a non-verbal communications class I had back in 1984. :wink:

16

Once again, ladies and gentlemen: Genius and madness, the mysterious link between them.

Exhibit A: Jomo Mojo.

17

I guess engineer_comp_geek’s evidence gives some insight into my dark green Accord. Does it make any difference that it was my second choice? (And thanks for the observation about my post, Jomo. I was virtually convinced that my posts can’t be seen by anyone else.)