Every single time I turn the climate control fan on the A/C compressor also comes on. This happens even if I have the temperature control turned up to 90 degrees. When the system is off I've tried turning on the fan by pressing the fan button, the mode button, and the auto button. Going from off to on always turns on the compressor no matter what button I use. If I manually press the A/C to turn off the compressor it will stay off, but everytime I go from fan off to fan on the A/C comes on. This seems backwards to me. I can accept the A/C coming on if I select the AUTO mode, but I cannot see why the A/C should come on if I just turn the system on by hitting a fan control button.

Does anyone else have a problem with this? Its driving me crazy.

 

I think you can program it to come on how ever you want. A/C on or off, ect. Check you owners manual on how to program it. It might have something to do with setting the memory for your key or FOB.

 

You need to set it up (program) so that when you turn on the CC only the fan will come on. Also the AC lite will come on for the defrost as well. Unless I going crazy I believe this is correct.

 

>You need to set it up (program) so that when you turn on the
>CC only the fan will come on.

I do not remember seeing this in the owners manual. I will check again in a few minutes.


>Also the AC lite will come on for the defrost as well.

This I know, and I am ok with. The AC is used for defrost and defog to remove moisture. I am turning on the fan with the outside air mode button on, and the vent delivery mode set to floorboard heat. The AC comes on every time even with these settings.

 

The memory feature will remember seat position,mirror position,radio station,and climate control settings present when last programmed (or "set").
Try setting up your climate control just exactly like you want it to be when
you start your car and then pressing the memory button (that corresponds
with the FOB you're using) and holding it down until it flashs twice.The car will
now "remember" your preference and this should cure your problem. :)
Also remember for memory seats (and maybe other features) it will be
necessary for you to "unlock" your car useing the FOB that you carry even if it's not locked.This tells the car who's about to climb in and it will remember all
the associated presets. Pretty Cool! :yesnod:

 

The A/C compressor will come on with heat, defrost and maybe a few other settings, this happens in my M5, as well as my Overland, this is normal...... well it's not normal to me, but it's normal among new cars.

 

>Try setting up your climate control just exactly like you
>want it to be when you start your car and then
>pressing the memory button

The memory feature only remembers the A/C compressor settings if you leave the climate control on when you turn off the car. My question was how to stop the A/C from coming on when I switch the climate controls from full off to on while the car is running.

I do not leave the climate controls on all the time, and I turn them off before I turn off the car. I find it irritating that every time I turn my climate controls on I get A/C, no matter what I try.

For example - I have the system set in floorboard heat mode with the air circulation set to outside mode and the temp set to 90 degrees, I turn the compressor off and it stays off. I turn the entire system off while I am driving. I then turn the system on by pressing a fan button or the mode button. The system turns on in floorboard mode, outside air, 90 degrees, compressor on. The compressor always turns on when I switch the system on, no matter what I try.

 

I'm not so sure that just because the A/C light is on, that the compressor is automatically activated. I think it's more of an "A/C armed" indicator, meaning that the system will come if it is required. I'm not even sure that A/C means just cooling, it may also indicate the availability of heating as well, since it comes on even in cold temperature conditions. I'm certain that the compressor only comes on in response to demand. If the outside air temp feeding into the cabin is enough to maintain the temp set in the climate control, the compressor is not going to come on, nor is the compressor running just because the A/C light is on on the control.

Most cars with automatic climate controls default to some level of automatic function, and require you to shut off those features you do not want. Some don't even have an indicator light for the A/C system at all. This one is not that much different than the Jaguar or BMW systems. Any time you turn the system "off", turning it back on will start some automatic features.

In this case the way to turn the A/C on in manual mode, without the automatic climate control system operating it, is to hit the fan switch. They had two choices, fan switch activates fan only, then you add A/C by hitting another button, or make the A/C come on with the fan as the default, requiring the second button input to disable the A/C. Considering the Vette is predominantly a summer car, I can see how they might assume the latter. They probably have some statistical data showing that the majority of customers wanted A/C manual mode when they hit the fan switch from the "off" condition... who knows.

The best bet is to not turn off the system completely while driving, just turn the fan mode down to its lowest setting and leave it on. I leave mine on with the fan in the lowest setting as a matter of default. This way the system does not re-activate the A/C armed feature.


[Modified by kwillmorth, 4:12 PM 4/5/2002]

 

The compressor is coming on, I can feel it and hear it engage the compressor clutch. I am sure it will cycle with respect to low-side pressure, but the clutch
is ready to engage.

Another thing I noticed, If I select recirculation mode the climate controls will not allow me to disable the A/C. If I hit the A/C button while in recirc mode the AC button just flashes at me. This is true in all air delivery modes (floorboard, vents, etc..)

 

Might think about installing a switch in the dash to disable the A/C compressor manually. A small toggle located in the blank where the fog-light controls would normally go could be installed easily to simply disable the A/C compressor altogether. Then you can ignore the dash light. Only when you actually want the A/C would you turn in back on. It's really easy to do, as it just cuts power to the clutch. I don't know any other way to disable the activation without hiring an electronics wizard to reverse the default control action. Sort of the same deal as with the traction/active handling control, you can get it wired to default to "off" with the switch turning it on.

I've done a switch in 2 cars. One where the A/C compressor was associated with everything from defrost to heating (to rid the air of humidity I guess), but I was living in Minnesota and the A/C system would completely leak down if run in sub zero temps (lovely Jaguar XJS engineering.) The other was a drag car, where we just wanted to make abolsutely sure the compressor was totally disengaged on a run.

 

You could put a switch in if you really want, BUT CONSIDER THIS:
You have an AUTOMATIC temp control heating/cooling system, which controls the "cabin" temp to the temp you set, it is not trying to set the air discharge temp. That means you have to be able to supply cool air quickly when the controller calls for it, and you cannot do that if you have to wait for the ac compressor system to get up to pressure and down to temp. The system therefore wants to have the heat coil hot and the cooling coil cold in order to get the mix of air it needs to maintain cabin temp. Also when in Recirc, you have cooling to rid of moisture and heat, since there is not outside air coming in.
Truthfully, its a function of the type of sophisticated AC/Heating systems we have in our cars, and GM's AC/Heating guys are among the BEST!

 

rbartick, I too find this "feature" rather annoying, but I've learned to live with it. In my opinion it's a bad design and GM should've made the climate control such that it remembers all of your settings even after pressing the Off button.

 

>You could put a switch in if you really want
>Truthfully, its a function of the type of
>sophisticated AC/Heating systems we have in our
>cars, and GM's AC/Heating guys are among the BEST!

As I said above I am not considering an AC clutch switch. FWIW, I don't have a problem with the AC coming on when I am in FULL or partial AUTO (auto air delivery), even if I have the temperature set at 90 degrees. I think that having the compressor come on every time I turn on the system in manual floorboard heat or manual vent heating mode is silly.


[Modified by rbartick, 1:07 PM 4/5/2002]

 

there's no question about it, the setup blows. Do what you want, stand on your head if you want, and the AC compressor WILL come on. Engineers at GM confuse Vette owners with Cadillac owners and the AC is set to come on. Play hell trying to turn it off with one press of one button. I will even give you an extra try for grins. Oh, and you gotta love the dual climate control in a 4 ft wide cabin.

 

There is a way! (But it has a limitation.)

The ONLY way to turn on the climate control system without the A/C coming on is via the memory feature.
Do the following:
While idleing:
Set the temp, fan speed, etc. as desired with A/C OFF... save this in one of the memories.
Turn off climate control
Now, instead of hitting any button on the climate control, hit the Memory "X" button (i.e. "1" or "2" on the door - where you saved the settings above)
Climate control will turn on, but A/C will not.
This works (obviously) after turing car off and restarting. Unlocking the car with the Key Fob does not turn on the system... you have to hit Memory X after the car is started.

Now, here's the one (pretty nasty) limitation... the memory feature gets deactivated at some speed... i haven't played around enough to figure out exactly when this is... idleing or moving slowly, this works, but hitting Memory "1" on the freeway has no affect (I guess they dont want your seat around at speed)...

So basically everytime you start the car... decide if you want the climate control in "Manual Mode" (hit memory button), or "Auto Mode" (hit one of the climate control buttons).

 

I agree with you guys, but like beggar I have learned to live with it.

The only time I have been able to use the system and not have the compressor come on is when the outside temperature is somewhat colder than about 20 degrees F. Even then it will cycle on if the interior humidity reaches a certain threshold, but after the interior air is dried, it will cycle off automatically. I suspect the system is activated by humidity. Cold air is also dry air.

It is not often that cold here so I have only rarely seen this happen and I'm not sure what the precise temperature/humidity threshold is.

Works great in hot weather.

And starting tomorrow it will be hot here for about 6 months. :D

 

I totally agree... but I changed my habits a little... because I dont think the AC will last (for as long as I want to own this car)... with it cycling ON every time I turn the CC system on and then 2 seconds later I turn the thing off. Repeat this a few times a day... over a number of years... (my car is a daily driver) :(

 

I like Dreamin's idea. Tried it today, works perfect. Want the fan on, I just hit the mem2 button. Now I have one mem for my main seat position, one for the seat all the way back for getting the lap belt tight for track days, and now the third for fan, non A?C function.

Thanks! :cool: :cheers:

 

Here's how to " lock out" the A/C compressor : set your desired fan speed and air flow , push A/C button OFF , the hit MODE button twice , quickly. You're done ! Changing the TEMP setting doesn't default it, either. To resume ususal irritating mode, just push AUTO again.

 

Re: Stupid Climate Control 'feature' (kwillmorth) (usroute66 MKW)

Here's how to " lock out" the A/C compressor : set your desired fan speed and air flow , push A/C button OFF , the hit MODE button twice , quickly. You're done ! Changing the TEMP setting doesn't default it, either. To resume ususal irritating mode, just push AUTO again.

That is exactly what I have been hoping for: a simple way to disable the A/C. I am going to try this today.

How did you learn about this?

Thanks, :cheers: