how do I turn on my heater??

You are kidding, right?
Just increase the cabin temperature.
Lower left steering wheel control, or MFD Climate control page.

Page 293-owners manual.

 

if it's cold out, i prefer 72 to 76 degrees the automatic climate control aka A/C keeps the cabin temp pretty well stabilized.

 

I am also unable to turn on heater in Prius 2010 please help

 

on a 2010, it depends on the package and country. generally speaking, you have a fan switch that must be on at least low, then a temperature switch that you can set up to 80 degrees f, or high, which is the highest setting above 80.

 

I have an 06. I either hit the up/down arrows on the steering wheel temp control, or tap the climate screen arrow up/down to the desired temp. Normally, I leave the AC feature off and the climate on Auto. I'll flip the AC on when it is raining/humid, or in summer.

 

He's right. It's counter-intuitive.

Assuming the cabin temperature is below the temperature set in the HVAC system...

If I punch the steering wheel button for "A/C Auto", heat is certainly generated. However, if I enter the "Climate" panel of the MFD, The "A/C" "button" is lit up, indicating the compressor is engaged.

While I'm aware that in certain high-humidity situations it can be useful to engage the compressor, I live in a desert and it's never humid.

When I want heat, I go into the climate panel and manually switch off the compressor. It serves no purpose.

 

The A/C button lets you control whether the compressor can be engaged. It comes on by default if you press A/C AUTO, so the compressor will be allowed to run if conditions demand. You can press it to turn the light off, meaning the compressor won't be used. But having it lit up doesn't mean the compressor is in use, only that it can be.

 

Ah, that is good to know... except that implies there is know way to know if the compressor is engaged. Can that be right??

 

I think if the AC button light is lit, it's pretty much certain the compressor will be cycling on and off. Barring near-freezing temps? Or extreme low humidity?? Monitoring the AC compressor with ScanGuage (XGauge ACWatts), it would start and stop about once a minute, at varying wattage levels.

The AC compressor can also run in a sort of "stealth" mode: if mode is set to heat/defog. Even with the AC button light off I would see the compressor cycling on/off, similar to above albeit maybe at lower wattages.

Maybe it's specific to my Canadian 2010 model year, or 2010~2011 (pre mid-gen upgrade), not sure, but with mine: AC button does not light up with push of the Auto button. If it's off it stays off, and if it's on it stays on, when you push Auto.

Again, as mentioned above, it may run (without AC button light glowing) if mode is set to heat/defog.

 

maybe they don't install heaters in pakistan

 

probably do. We've been watching a lot of Turkish who-dunnit series, and sometimes everybody's bundled up, and there's slushy snow.

 

yeah, currently 47f in karachi and 67f in islamabad. in LA they call that COLD!

 

This rings a bell ... maybe there was a thread where we even found a customizable setting (in some years?) for whether it comes on by default with AUTO.

 

Yeah I like that AC behaviour: if I didn't want it on before, chances are I don't want it on next time I turn the system on. Status quo.

Basically, I'd like a system where I could turn it on and it would restore all the settings as they were last time.

And it's not quite there, by a long shot. It does maintain AC setting (at least on mine), but unless I'm mistaken the only way to turn on an "off" system is to hit the Auto button, and (like it's name) sets everything automatically.

A specific scenario where that backfires for me:

When the car is partially warmed, I find it'll shut the engine down at red lights, IF the heat/vent system is completely off *. So I'll do this. Then with green light I have to glance down (and I'm trying to navigate through an intersection too, so this is a distraction) and hit the Auto button. And then, since I've often got mode overridden to heat/defog, I need to glance down a second time (double the distraction), to hit the mode button, which (thankfully) seems to always go to your previous choice with just one button choice.

I'm not enamoured with the 3rd gen Prius controls, basically tolerate and accommodate it. Would much prefer a tactile/ergonomic system, with easy-to-find and usable without looking dials and sliders. Base model Honda Fit is a good example.

* Sometimes I can get the engine to shut down by just lowering cabin temp, maybe as low as possible. That's my first tactic.