wet phone

[clare]

On "climate control" equipped cars like my wife's 2002 Taurus you just set the temperature and the car's computer decides whether you need heat or cooling and controls the compressor accordingly - turning the AC on when defrost is sellected regardless of temperature. It is impossible to turn off the AC from the control panel without turning off the climate control completely (if even that is possible - don't think it is)

On my 1996 Ranger I have total control of the AC - but that is because I installed it myself - bodged together from an assortment of new and used parts with the express duty of cooling the cab when I tell it to.

No recirc, and no "smart controls" - just a pushbutton switch on the dash.

[clare]

Removing the AC clutch fuse, disconnecting the compressor, or removing the belt "makes sure the AC is off".

Driving with the HVAC system on defrost mode ensures the AC compressor will at least cycle on and off - or run constantly, depending on the type of AC control implemented

[trader_4]

I guess if you just leave it on defrost, even if the AC is not on, it probably wouldn't fog up again as long as enough hot air is blowing on it. But most people want to switch to heat mode, maintain a comfortable temp and then in my experience it will fog up again many times, like you say. In fact, "defrost" is really only part of the problem. In my driving, it's far more common for the windshield to just fog up while driving. It only needs to really be defrosted if it's been parked outside in freezing temps.

The implementation of whether you can disable AC while in defrost will probably vary among cars. But I would think most do force AC on, because they know most people don't understand the concept, would turn off the AC, so it's better to just force it on. If it's below freezing I think they disable the AC at that point anyway.

[micky]

Different outlooks on argumentation snipped.

You know, I didn't even see it as a smiley. It was more like someone spilled crumbs on the screen. I didn't know it was a smiley until just now.

Once they clear, they never fog up again, at least with the defroster on, AC or no AC.

[micky]

That's a whole other thread, for when I have time.

[micky]

Well I can't exhume my '88 or '95 Lebarons, at least not without a court order and I think I need the agreement of the prior owner.

But I can make some tests on the Toyota. It will take a while because I've been having trouble telling cool from warm lately. That is, the air from the dash (without defrost) felt cool when I thought it should be warm.

[micky]

Wow. I've been complaining about the Toyota, which turns things on automatically but at least it lets me turn them off. Each time, of course.

Yeah, I hate smart controls. My friend Paul warned me, but when the rest of the used car is top of the line, you get stuck with climate control.

So I think it depends on whether it's summer or winter, or on some other setting, but half the time, it starts up with recirculate on. I never want recirc on unless it's over 96 out. (It's a convertible so I don't use the AC until it's over 95.)

And it keeps turning the AC on when I put the defrost on -- oh yeah, that's where we all came in.

I think there's a third thing.

Well there's a question at least.

SAy I set the AC for 70. What happens when the car gets to 70. I think in another post you say the compressor might stay running, but does that mean it just moves the hot/cold door so it's mixing hot air with cold air, to keep it at 70. Surely that's a waste of fuel.

And you said on other cars the compressor cluth disengages. That sounds good, but the makers dobn't advertise who does what.

[DerbyDad03]

How about we split the difference and discuss a 1990 Labaron? According to the "tech expert" answering a question in the following thread, it is norma l for the A/C compressor to come on when in defrost mode. I gotta assume it was the same for the 95 since it was later model.

Maybe I'm reading too much into the statements in that thread, but it sure seems to me to mean that you can't turn off the A/C when in defrost mode.

[DerbyDad03]

...a lot snipped...

On this we agree. I have 4 vehicles. The Odyssey (my daily driver) is the o nly one with a fully automatic climate control system. I love everything el se about the vehicle expect for that. I long for the days of 3 dials and 1 button: Temp control dial, fan speed dial, mode dial, A/C button. OK, maybe a Max A/C button too. That's all we really need. There are far too many va riables involved to expect a vehicle to maintain a given temperature automa tically. There is no such thing as "set it and forget it" and least not in my experience.

...snip...

True dat!

Just like your Labaron did ;-)

[micky]

Maybe so. I remember now that I didn't have climate control in any of the Lebarons. Because I guess Chryslerr makes a lot of convertibles and doesn't insist that they are the top of the line. (None are cheap, but they don't all have leather seats and climate control, for example.)

But I have to tell you, after 30 years of avoiding cloth seats because I thought they would soak up the rain, I really like them. They dried out in half a day (because the top was only down in the summer, so it was warm) and the seats were the most comfortable I've had. After I had abdominal surgery, the car was more comfortable than the bed or any seat in the house.

That's what I think people are saying.

But it turned out to be easier to test the 2000 Toyota Solara Convertible than I expected. I turned on the defrost and the light went on on the AC button. I pushed the button while looking at the tach, and I could see the speed go down a little, and the AC light went off. I pushed it again, the AC lightwent on, and I saw the engine speed up a little. So I think turuing it off turns it off.

[micky]

Exactly. If iit was set it and forget it, it woudl probably be worth thee inconveniences, and maybe they wouldn't even be inconvenient, because I'd forgotten it. But cars are not like houses.

I stil fiddle with it a lot and I'm not even sure what effect the controls have.

Yet they've been pushing this as luxury for what, 30, 40 years?

[clare]

They just copied Mitsubishi -- ugly mugs.

>

[clare]

Well, I KNOW my '95 LeBaron Mark Cross Town and Country Wagom ran the AC any time the defrost was run, down to about -10C

And I installed hundreds of Toyota AC systems -

[clare]

It mixes hot and cold air and either throttles the AC or cycles the compressor, depending on the design of the system.

Doesn't matter - cycling the cliutch or throttling the AC (adjusting the orifice) uses about the same amount of power, and throttling doesn't wear out the compressor clutch

[clare]

You read it correctly

[clare]

The climate control on my wife's 02 Taurus is a lot closer to "set it and forget it" than the HVAC system at the office!!!! If you tinker with the controls on the Taurus you have to keep tinkering because you overshoot. Just set it to 18C and leave it, and the car is always comfortable except when you start up untoll it gets up or down to temp. Setting it to 16 doesn't cool it any faster, and setting it to 25C doesn't heat it up any faster. Can't get my wife convinced though, so all od a sudden it's either too hot or too cold because she's played with the settings again!!!!

Stop fiddling - you are just like my wife. Set it and forget it.

And do you know what "max AC does? It just puts the system in recirculate mode to cool quicker (and dry your sweat quicker)

[Tony Hwang]

What's the worry? Most car AC has automatic mode. Set it and forget. Very seldom need to manually intervene.

[Ed Pawlowski]

Maybe where you live, not here in New England. They can fog numerous times in the right weather and of you change altitude on the hills. I can go from sun to rain to snow to fog to sun all in five miles.

[Ed Pawlowski]

OMG, I've wasted hours of my life trying to explain that to people. Same with the thermostat at work. It is just an automated switch.

I finally convinced one person by having them turn a light on. Want it brighter? Push the switch really hard.

[DerbyDad03]

he only one with a fully automatic climate control system. I love everythin g else about the vehicle expect for that. I long for the days of 3 dials an d 1 button: Temp control dial, fan speed dial, mode dial, A/C button. OK, m aybe a Max A/C button too. That's all we really need. There are far too man y variables involved to expect a vehicle to maintain a given temperature au tomatically. There is no such thing as "set it and forget it" and least not in my experience.

I don't know about micky, but I don't fiddle with it for the sake of fiddli ng. I fiddle with it because the vehicle does not maintain (or my body does n't think it maintains) a steady temperature.

I don't fiddle with my house stat, unless I really want it warmer or colder based on what I'm wearing or doing. However, I can be driving my Odyssey o n the highway for hours, doing the same thing (driving) and wearing the sam e clothes, and will need to adjust the temp on occasion to remain comfortab le.

I don't have any long (hours long) trips planned for a few weeks, but I wil l a perform a few local tests. I have a cooking thermometer with a wired pr obe. It reacts to changes in air temp very rapidly. I'll hang it and monito r it to see if I can prove myself right or wrong.

In mid-August I'll be doing a 950 mile double-college-move trip (2 daughter s both moving on the same weekend) that will be a great time to really mon itor the cabin temperature.

We'll see.