New owner question

Easy,

Turn on the A/C, go to the climate menu, press the A/C on the MFD (light should go out), fan adjustments will work as expected.

Make sure the selection for fresh air (bottom left) is selected vs. recirculate.

Enjoy.

 

You also must still set an appropriate temp.

PITA. A "vent" button on the MFD would be welcome.

 

Also, set temp to outside temperature. If outside temp is below 65, you cannot set the system temp below 65 because it will kick in to max cool and that will bump up the fan speed. If the outside temp is above 85 you cannot match that temp with the system because it will kick in to max hot above 85. However you can make the A/C system full manual by selecting the air outlet, selecting your fan speed and turning off the a/c. However temp control is still going to be automatic, try to match outside temp.

 

I've only had my Prius for a week, but this is how I run the fan without the AC:

Go to Climate.

Make sure Auto is Off

Go to AC button - if there is a yellow line across the top of the button, the AC is on. Touch the AC button and the yellow line should go away and the AC is off.

Select the fan speed you want.

 

You are right. With the AC off the automatic setting, the temp button does nothing to the AC. However, this is a way to set the heater manually. Set the temp higher than ambient, and the heater will come on. Set it below ambient, and nothing will happen if the yellow bar is off above the AC button..

You can set the fan from low to high, and you can set the recirc versus outside air.

 

In order to get outside air, the fan must be on (auto or a speed setting of your choice; if it's OFF, the vent closes regardless of what the fresh/recirc setting is), and the mode switch should be set to high-level (the upper vents), and you may still need to fiddle with the temperature setting, otherwise the A/C computer (which still controls everything even though the compressor may not be running) overrides and you may end up getting recirculated air vs. outside air..

The climate control system on the Prius is easily the most annoying thing about the car..

 

I don

I don't believe so. While driving 70MPH, I turned off my HVAC using the steering wheel control. It was on Auto, so it went to Off. I had it on Recirc, so it stayed there. No air flowing from vents.
Set Recirc to Fresh, air is felt coming in.

A good way to really find out is try the recirc while behind a smelly diesel truck. Fresh - smell. Recir, no smell.

 

The NCF is confusing as hell where it concerns the A/C and ventilation system operation.. The last time I read it, it seemed to suggest that the vent is closed if the blower is off, but looking at the text and diagrams yet another time, perhaps the other linkages to the mode control can also override..

In any case, the air flow is very small without the fan going- I tried it but couldn't swear to whether there is a flow or not, but then that could also be related to the speed-dependent nature of the vent- there's a graph in the NCF that seems to suggest a speed dependent hysteresis loop for opening and closing the vent (opens when you slow below a certain speed, and closes when you increase speed over a certain threshold)

I'll reiterate that this is easily the worst designed system on the Prius..

 

Actually, I don't think it's that bad a system at all. In fact, I think it's a pretty good system. It's a combination automatic system, if you want auto. But it's also a totally manual system at the same time if you want that. I've had (one) car that was "auto only" and it was hard to do things manually, but of course most of my cars that had working AC were totally manual. This car does both well. No completely intuitive, but once you get the hang of it it's understandable.

And yes, when you have the refresh button on, and the fan speed zero, the air coming out of the vents is low, but it definitely IS coming out. I tried it at 70 MPH and there is no doubt air is coming out. Enough for an air change, but no where near enough to be "refreshed".


And on my 04 Prius, if you have the fans off, the temperature buttons and AC button are greyed out. But if you have the fans on any speed, the AC button comes live, and the temp buttons are live. If you make sure the AC is off, that temp button is still live, but it had no affect on air temp until I reached max hot, and then very hot air blew out. But from 84 degrees all the way down to max cold, there was zero change in the temperature of the air coming out, unless the AC was on.

So with the AC off, that temperature button only affects the heater, giving you a manual system.

 

My biggest beef is that the vent is nowhere near enough compared to my old Corolla... The specific scenario where the Prius system fails spectacularly in my eyes is in damp rainy weather..

On my old Corolla, simply setting the mode to defog and opening the outside air vent was sufficient in most cases to keep the windshield clear. Sometimes you also needed to turn the heat up, but in most cases, the extra warmth was welcome.

With the Prius, the defrost mode does automatically open the fresh air vent, but it also forces the A/C on (but on the Classic, the A/C light stays "off" and you cannot manually turn the A/C off- I understand this is different on the HSD and you can turn the A/C off manually). The A/C does turn off if you switch the fan off or the mode to FOOT/DEF, but then this also places the vent under automated control (opens and closes depending on temperature, speed, and other factors) and the low flow in this case does not allow enough outside air in to adequately defog the windows and the interior rapidly begins to feel stuffy and the windows fog over.. Opening the windows will help, but lets the rain in, so you're forced to use A/C to keep the windows clear and you suffer the MPG hit when you really don't need to..

As I've posted elsewhere, the system annoys me enough that I keep wanting to tear out the A/C ECU and put in manual cables to control the vents myself- environmental settings are such a personal thing that I doubt that any automated system can fully satisfy everybody, whereas a fully manual system may require some tweaking and fiddling, but you can generally find a setting that makes you reasonably comfortable..

 

<div class='quotetop'>QUOTE(c4 @ Aug 9 2005, 01:35 PM) [snapback]114962[/snapback]</div>

Naw, you want vent? My 1963 Dodge Dart had vents. A vent box under the dash above the driver's left leg and another above the passenger's right leg. Five-inch-square manual doors: you either opened or closed them. We used to call them "Hurricane Doors."

But I'm just being silly.

 

<div class='quotetop'>QUOTE(DanMan32 @ Aug 9 2005, 01:25 PM) [snapback]114878[/snapback]</div>

i'm sure the vent only close when recirc is on. pass a dead skunk once a week, you'll figure it out.