Jerry MB230K

All summer long, left a/c in auto and all worked OK. Now, I push EC ( to turn off A/C ), and even after 5 minutes, A/C is still on. Also, when I turned knob down to 64 ( 72 outside temp ) , heat was on with EC ( and not auto ).... all awry .... not impressed.

Anyway noticing a/c control problems ?

TimmyC230boy

EC button isnt what you use for heat. For heat just turn knobs to 80 and turn up fan speed. Also on the center vents make sure the blue dial is off or else cold air will be mixed with the hot air.

SoCal240/6

He isn't trying to use the EC button for heat.

If I am reading his post correctly, he is saying that he has the following settings:

Auto: OFF (the light is off)
EC: ON (the light is on)
Temp: Dial set to 64

And, with those settings, and an outside temp of 72, the ventilation system is putting out heat.

If that's the case, then it does sound like something is wrong. You shouldn't be getting heated air under those conditions.

And, on the other problem, yes, it does sound like there is a problem if the compressor is not turning off when you press EC. How about after 10 minutes, are you still getting cold air? If so, the compressor is not shutting off.

Sounds like you are in luck, you have 79 cents of "free" cookies coming your way soon!!

Jerry MB230K

to timmy230boy ... why don't you read what I wrote.. I'm not trying to get heat with EC

Jerry MB230K

thank you socal240..you got it right !

TimmyC230boy

I have had 6 hours of CE classes today. I'm beat. lol Yeah that sounds like you may be visiting a dealer soon.

MarkL

Jerry, we've noticed that the compressor seems not to shut off immediately upon engaging EC. It can take about 10-15 minutes before the cold air "stops", and ambient air is delivered. Also, I think some people had complained earlier that it seems there's more warmth to the ambient air than they expected -- maybe the air is directed over warm surfaces before it gets to the vents. Not sure you have a problem.

tommy

I have the same issue with the a/c putting out cold air. Which is why I make sure to turn it off before I turn off the car, if I'm not going to re-use it on the next time that I start the car. I think that, if you can shut off the car, and start it up again, the hvac system will reset without a/c (assuming that's possible when you decide to switch off a/c - don't try this on I-95! )

As far as the heat, it does sound like you've got issues. It's cold enough in the morning for you to try putting it on 80 when it's 60 out - see what you get; try several different combos of outside/inside temps, and document them for that trip to the dealer that sounds imminent.

Jerry MB230K

to TimmyC230Boy...what are CE classes ?

MarkL

Right. I've tried switching EC on before starting while the key is in position 1 or 2 (LED's lit), but the cold air is still produced for a while. You either have to do what Tommy said, turn on EC before you shutdown, or engage it and turn ignition off and back on before starting up. The switch status is apparently checked when the ignition is first energized.

I think he was trying the opposite -- to get cool (i.e., non-heated) air when the ambient temp was not very hot. Tommy, didn't you have this issue when you first got your car? Seem to remember you complained that you couldn't get what seemed like non-heated ambient air...

p010sp0rt8

CE - computer engineering?? (i'm one of them ce ppl too)

but.. i was wondeirn.. on my c230k, when i turn the car on and the EC button is pushed i get warm air coming from the vents... (temp **** turned to 60 or whatever the lowest is) and then.. when i press ec off and back on the air becomes cool and stays cool... i find this very odd...

SoCal240/6

Yes, I agree with all of that.

The warmth in the "ambient" air is annoying, though. In these cars, its difficult to get just plain, cool, outside air flowing through the vents. Not only does the air seem somewhat heated, it also seems very humid.

A bummer, esp. here in So. Cal. where for probably 300 days a year, just plain ol' outside air is all you need coming through the vents.

SoCal240/6

That's the way its supposed to work. When you press EC you are turning off the compressor, so the air is no longer cooled. When you turn EC off, you are turning the compressor back on, thus the cold air.

MarkL

Exactly. People should just think of the EC function as the opposite of "AC" switch on other cars (w/ a delay in shutting off compressor). Or, realize that EC stands for ECONOMY which means AC compressor is off for better gas mileage, etc.

Apollo

My understanding is that EC stands for economy so that you keep your fuel usage down by not using the compressor. Auto still tries to maintain the car temp without the air conditioning compressor, but it will only cool down the car up to the temp of the ambient air coming in.

SoCal240/6

Yup. Mostly.

Which in theory would be great, but in reality doesn't work so well because with the compressor turned off, the air that eventually comes out of the interior vents is far warmer and more humid than the outside, ambient air.

So, with EC on, it really doesn't "cool the car down to the temp of the ambient air coming in." Which is a bummer.

viper

Actually it could also be chemical engineering or civil engineering.

TimmyC230boy

Continuing Education. Mandated by state of NC

shtatc

The dealer told me that the EC mode works better in winter when you want to keep the inside of the car warmer for those times you go out and come back within a few minutes. Just on principal - I would not think it would work that well to keep the car cool. Correct me if I am wrong.

tommy

Well, it's alot easier than keeping it on auto, and pissing away nice cold air out of the windows and sunroof.

Unless you have the windows up all of the time, and what's fun about that?

Oh, Mark - good memory! I've just learned to keep the fan on low setting (totally turned off is not recommended), and the stream of slightly warmer air's not a big deal with the widows down and roof open.

avlis

Why not?

Jerry MB230K

thanks for all your posts...seems like the HVAC system is designed to work best when the windows are closed whether you're trying to cool ( with A/C ) or heat up the interior.

Jerry MB230K

any one know where exactly is the temperature sensor inside the car ?

tommy

I think that there's something in the manual about it (if I were positive, I'd have to do my favorite response, RTFM! ), but it keeps air flowing through the ventilation system, which reduces the chance of mold /condensation occuring in the system.

MarkL

Don't want to start on a tangent, but... I think you or your dealer might be confusing EC with the REST function. You can engage REST when you shut the car off which will provide residual heat (on cool days) at a low fan setting. In summer, it tries to provide residual cool air, but that becomes warm pretty quickly. EC simply turns off the A/C compressor. True, in winter, you could leave EC engaged since you won't need the compressor IN GENERAL. But, the system will disengage the compressor anyway when it's really cold outside, and besides, leaving the compressor on helps w/ avoiding fogging the windshield in certain conditions. BTW, I believe the REST function has been deleted for 2003.