Explain my Electronic Climate Control?

[gmrulz4u]

I've had my 89 Cutlass Supreme with Electronic Climate Control for almost 6 years now and for the first 5 or so I never used the Auto function on it, I would just try to control everything myself.

 

Well now I am liking the idea of just telling it what temperature to keep the cars interior at. It's pretty cool actually. But I am not understanding a few things.

 

1) What does the "AUTO" button actually do? If I press it, does it just control which vents the air comes out of?

 

2) If I set the temp to say 24 celcius, and then press the "BI LEVEL" button, I notice that the fan speed will change automatically, even though I never pressed the "AUTO" button?

 

3) Why, after pressing the "AUTO" button does it seem to use ONLY the floor vents and never the dash ones? Is this normal?

 

I am just kind of confused as to how the whole thing actually works and I no longer have the Owners Manual for it.

 

Thanks!

[Pyle]

Not an expert on this, but i'll give it a shot

 

1) think the auto button just gets your car to the temp it is set at, I dont think it actually controls which vents the flow comes out of.

 

2) been a while since I have been in a car with "bi-level" but I thought that was just a setting to set the flow to come out both the floor vents and dash vents. It may appear as though the fan speed has changed, but actually it is now splitting up the amount of air to the top and bottom, hence it seems like it is not blowing as hard.

 

3) i dunno, might have something to do with the ability to warm your car up better using floor vents...?

 

Anyone else, was I close?!? :?

[GutlessSupreme]

Pyle, 1 and 2 are right.

 

3) Why, after pressing the "AUTO" button does it seem to use ONLY the floor vents and never the dash ones? Is this normal?

 

Sometimes when using anything more than very light throttle, a vacuum leak will cause the dash vents to shut and only the floor vents will remain open. It's extremely common on these cars. Usually the problem is the vacuum reservoir located under the driver side fender. It's the black, round plastic ball, like 6 inches in diameter. If you can find a part number, see if you can get it new from the dealer. Junkyard ones are usually all bad too I've found. Shouldn't cost too much new.

[1990lumina]

I hate electronic climate control lol, I like manual setting...easier and you don't have to take your eyes off the road to use it most of the time.

 

that being siad I posted a picture of this plastic ball thingy a couple months ago if you need it I can search for u

[Justin]

It's normal for it to only use the floor vents and the defrost vents when it's cold out, the heat coming from two spots works better. I leave my car on AUTO 99% of the time, with the thermostat set at about 72. There is no reason for you to set it to 90 degrees, then drop it to 70ish when it warms up, it won't warm up any sooner. Working in a dealership you find that maybe 1/3 of the population isn't completely clueless when it comes to auto climate control. People need to READ THEIR MANUALS.

[stockgp]

so, being that i'm swapping an 97 cutlass auto climate control into my gp, does it automatically turn on ac? i assume it would, instead of just turning the temp down.

[Crazy K]

so, being that i'm swapping an 97 cutlass auto climate control into my gp, does it automatically turn on ac? i assume it would, instead of just turning the temp down.

I wanna see some pics! do you have it working?

[stockgp]

i have it working without the dual zone part. i went to get the bottom half of the airbox and couldn't figure out how to remove it. i was breaking it, so i left it until someone can tell me how to get it out. right now it's working an ordinary hvac, but it is funcioning.

 

here are the last pics i took:

 

http://www.w-body.com/forum/viewtopic.php?t=28807

[pitzel]

Basically the algorithim with 'auto' is as follows:

 

When interior temp > exterior temp:

 

if desired_temp & exterior_temp < interior_temp

then engage upper_vents & engage_airconditioner

 

else if desired_temp < interior_temp & exterior_temp

then engage upper_vents & engage_external_airsupply

 

 

When interior_temp < exterior_temp

 

if desired_temp > exterior_temp & (engine_temp > 60degC)

then engage lower_vents & engage_heater

 

else

{do nothing until engine_temp > 60degC}

 

 

 

So basically, it will air condition if the outside temperature is greater than the desired inside temperature. It will vent external air to the interior if the external temperature is less than the internal temperature. All venting/air conditioning operations are done through the upper vents.

 

It will heat if the external temperature is less than the desired temperature, but the fan won't start for the heater until the engine reaches 60degC water temperature (however, defrost overrides the 60degC cutout).

 

The magnitude of the fan setting is derived from the temperature difference between the desired setting, and the actual temperature as recorded from the inside sensor. Of course, over-rideable by the user by merely setting the fan setting.

[gmrulz4u]

Thanks:)

 

So then basically when it's winter, the AUTO function will never use the Dash Vents...?

 

The part that confused me the most was the other day when I lowered the desired temp from 32 celcius to 24, but left it on BI-LEV, I "thought" that the fan would stay full blast, the way I had it, but, the system automatically started to lower the fan speed, even though I never pressed the AUTO button but simply just changed the desired interior temp.

 

So I guess that if you really WANT the warm air to blow from the dash vents, but still have the system control air fan speed, you can do so...

[jeremy]

I loved the dual auto climate controls in my cutty.....I used it all the time

[cutlassdude96]

I loved the dual auto climate controls in my cutty.....I used it all the time

 

I do too

[GnatGoSplat]

So then basically when it's winter, the AUTO function will never use the Dash Vents...?

 

The part that confused me the most was the other day when I lowered the desired temp from 32 celcius to 24, but left it on BI-LEV, I "thought" that the fan would stay full blast, the way I had it, but, the system automatically started to lower the fan speed, even though I never pressed the AUTO button but simply just changed the desired interior temp.

 

Yes. AUTO will never use the dash vents when blowing heat, because it wants to heat the interior as quickly as possible. Since heat rises, it would be inefficient to use the dash vents, the floor vents are most efficient for heat. Likewise, since cool air is denser than warm air, the A/C will never use the floor vents in AUTO.

 

Changing the interior temp overrides manual fan control which is why the fan speed lowered.