Climate control, AC on when heating

[Artacoma]

When using the AUTO control in my van the AC snowflake comes on no matter what the temp setting is (heating or cooling), and the compressor cycles as well as the idle speed bump.
It looks to be the way it was designed to operate but seems counter intuitive .
Do you use the Auto setting with the AC on when heating /defrosting or do you bypass and use the manual temp setting?

[nxski]

I'm not sure if I understand exactly what's going on with your system. In my civic it was set-up to have the A/C turn when the defroster was turned on. There was a switch behind the dash that you could flick off to allow you to make this decision yourself. The idea is that the a/c does not create as much humidity and will defrost your windows more quickly.

[psilosin]

When using the AUTO control in my van the AC snowflake comes on no matter what the temp setting is (heating or cooling), and the compressor cycles as well as the idle speed bump.
It looks to be the way it was designed to operate but seems counter intuitive .
Do you use the Auto setting with the AC on when heating /defrosting or do you bypass and use the manual temp setting?

Yeah it is really annoying (especially when your AC is busted and screeches every time it activates). You need to hit the snowflake button on the panel to turn it off when running in Auto mode. Mardy warned that it is bad news to have the AC running when trying to heat in the winter, which makes turning on and off the heat via auto mode or even by cycling via the mode button a potential for damage every time if you forget to turn the AC off.

If there is a way to deactivate this 'feature' it would be great. I haven't figured out how. If not, it might be an idea to remove the AC belt for the winter as part of the winter preparation routine.

[thedjjack]

Most cars and trucks now run the Air-conditioner when the heat is on, especially defrost settings..

It drys the cabin air out and helps defrost the windows.

Fords have been doing this since the 1990s for sure.

This is most likely normal...You should be able to remove the power to the AC condenser the pulley does not activate.

Not sure why Mardy thinks this is bad for the system...all new cars do this to dry the air (it is actually helpful for rainy winters like Vancouver and helps pull moisture out (as we have learned is not good in the crystal light roofs!)

[jessef]

When using the AUTO control in my van the AC snowflake comes on no matter what the temp setting is (heating or cooling), and the compressor cycles as well as the idle speed bump.
It looks to be the way it was designed to operate but seems counter intuitive .
Do you use the Auto setting with the AC on when heating /defrosting or do you bypass and use the manual temp setting?

normal

takes less than 1/2 the time to defrost in auto mode with A/C on

like David said. removes moisture from inside and pretty much every modern (2000+ era) vehicle is the same

Mitsubishi as usual was ahead of the pack

[psilosin]

Mardy was pretty adamant about not running the AC with the heat on or bad things would happen. Mentioned it more than once.

I forgot ONCE to turn the AC off after turning on the heat (2nd day of owning the vehicle) I made it as far as Peachland from Westbank (~15 minutes) before my AC started squeeling like a stuck pig and has been busted ever since (AC clutch fried).

Either Mardy knows this is a weakness on the L400, or that is quite the coincidence. Maybe he knew my AC was on its way out when he sold it to me..who knows. I know when I get the AC fixed I will be very cautious from now on to make sure it is not on in the winter just in case...becasue these vans get friggin hot in the summer with only 2 windows that open lol .

Anyone have experience with just letting the AC run when heating in AUTO mode all winter long with no issues?

[nxski]

I run my van and my truck with A/C on until the windows are de-fogged no natter what the conditions. I turn the heat to full but the A/C button is on.

[Artacoma]

Thanks guys , I'm going to keep it on for now.
My AC crapped out on the road in California a few weeks ago, belt started screaming so I popped the hood a found the belt was quite loose and found a nice pair of needle nose pliers under my intercooler that someone left for me.I tightened the belt but it started screaming again the next day so I turned it off and made an appointment with CVI when I got back home 3 weeks later.
Driving around Victoria I turned on the AC and it seems to work fine now so I canceled with CVI.
Probably have to wait till 2012 to get hot enough to really test it now.

[jessef]

L400 A/C compressor is known to fail. Common issue on the russia/uk/oz forums.

I use 'auto' to defrost in the winter but not with the heat turned on.

Profister would be the SME (subject matter expert) to look into this.

[psilosin]

I notice many of you keep mentioning AC on when DEFROSTING.

The issue on the L400 with the digital climate station is that the AC comes on automatically when you activate the AUTOmatic climate control (ie heat) regardless if you also activate the defrost or not. This means unless you manually intervene and turn the AC off after selecting AUTO your AC will be continuously running the whole time you are driving around trying to heat yourself. Seperate topic completely from AC on while doing a windshield defrost.

[jessef]

auto mode kicks in A/C + front windshield defrost . both related.

like you said you have to press it again to deactivate the A/C 'snowflake' if you don't want the A/C to keep running while defrosting/demoisturing your interior.

[djelica]

I notice many of you keep mentioning AC on when DEFROSTING.

The issue on the L400 with the digital climate station is that the AC comes on automatically when you activate the AUTOmatic climate control (ie heat) regardless if you also activate the defrost or not. This means unless you manually intervene and turn the AC off after selecting AUTO your AC will be continuously running the whole time you are driving around trying to heat yourself. Seperate topic completely from AC on while doing a windshield defrost.

I noticed this also when I first got my L400.

Now when I turn the system "on" I just press one of the temperature buttons (up or down) or the fan buttons (up or down).

This will basically bring the system back "on" to where it was when it was last turned off.

(I tend to turn everything off before shutting down just in case it is cold out the next time time I start. I want all my battery power going to the glow plugs and starter [and the one reason I don't like daylight running lights but that is another thread]).

As far as I can tell the AC comes on with Auto, with Defrost and when you reduce the temperature to 17 degrees using the Decrease Temperature button (you can hear the chime when the AC comes on, and that's a good thing because seeing the system display in the sunny day time is a serious challenge and yet another potential thread).

Hope this helps,

Darren