Brian Nystrom wrote:

>
> This same subject was discussed just a few days ago.
>
> Untrue. The A/C dries the air, but that not only does no good when
> you're trying to clear the OUTSIDE of the windshield, it reduces the
> defroster's effectiveness. If you live up north, it sucks.
>
> If you use the defroster to clear the inside of the windshield, then
> switch to heat once it's clear, the moisture on the condenser coils gets
> pumped back into the interior of the car and fogs up the windows again.
> For that reason, I prefer to use heat to clear the windows in the winter.
>
> Having the A/C compressor running costs me at least 3 mpg in my Elantra.
> IMO, that's unacceptable for a "feature" that I don't even want.
>
> Unfortunately, this is no longer something that can be easily
> disconnected. I contacted Hyundai about it when I had a nasty experience
> with it, but they had nothing to offer. In '04 and up, US market
> vehicles, the only way to get around this is to splice a switch into the
> A/C control line that comes out of the heater control module, so you can
> manually turn the compressor off. It's an inexpensive modification, but
> it requires removal of the dash facia and a bit of wiring. The switch I
> used fits where the cigarette lighter was. Since the car has an
> accessory socket, I didn't mind sacrificing the lighter to get better
> defroster function.

From my understanding, after the temperature drops below a certain
temperature (usually about 32 degrees) the A/C compressor does not
switch on in the defrost mode.

John

 

Pete & Cindy wrote:
> odd I life up north.. and I have NO problem with that at all.. when in defog
> mode. ya just turn the temp up .. problem solved...

If only it were that simple. I got into a situation in freezing rain
where the defroster could not keep the windshield clear. Another 10 or
20 degrees in the temp of the air from the defroster would likely have
made all the difference in the world. Canadian market Hyundai vehicles
allow the A/C compressor to be switched off, which tells you something
about the effectiveness of this dubious "feature" in cold climates.

 

Pete & Cindy wrote:
> odd I life up north.. and I have NO problem with that at all.. when in defog
> mode. ya just turn the temp up .. problem solved...

If only it were that simple. I got into a situation in freezing rain
where the defroster could not keep the windshield clear. Another 10 or
20 degrees in the temp of the air from the defroster would likely have
made all the difference in the world. Canadian market Hyundai vehicles
allow the A/C compressor to be switched off, which tells you something
about the effectiveness of this dubious "feature" in cold climates.

 

Pete & Cindy wrote:
> odd I life up north.. and I have NO problem with that at all.. when in defog
> mode. ya just turn the temp up .. problem solved...

If only it were that simple. I got into a situation in freezing rain
where the defroster could not keep the windshield clear. Another 10 or
20 degrees in the temp of the air from the defroster would likely have
made all the difference in the world. Canadian market Hyundai vehicles
allow the A/C compressor to be switched off, which tells you something
about the effectiveness of this dubious "feature" in cold climates.

 

Matt Whiting wrote:
> Brian Nystrom wrote:
>
>> Having the A/C compressor running costs me at least 3 mpg in my
>> Elantra. IMO, that's unacceptable for a "feature" that I don't even want.
>
>
> Something is seriously wrong then with your vehicle. I've never seen
> the AC consume even 1 MPG on a modern car. Actually, on my minivans and
> pickup, I can't even tell the difference between using AC and not. I
> check every tank MPG all year around and the extra gas used by the AC in
> the summer is lost in the noise of the MPG readings.

Sorry Matt, but I'm not buying that and I've never heard anyone else
make such a claim. An A/C compressor takes several horspower to run,
which does impact fuel mileage. There is still a debate about whether
rolling down the windows reduces fuel mileage more than using the A/C,
but there is no debate about the fact that either one reduces fuel mileage.

Perhaps you do a lot more city driving than I do, where the mileage drop
is less obvious, but a 3 mpg drop on the highway is normal.

 

Matt Whiting wrote:
> Brian Nystrom wrote:
>
>> Having the A/C compressor running costs me at least 3 mpg in my
>> Elantra. IMO, that's unacceptable for a "feature" that I don't even want.
>
>
> Something is seriously wrong then with your vehicle. I've never seen
> the AC consume even 1 MPG on a modern car. Actually, on my minivans and
> pickup, I can't even tell the difference between using AC and not. I
> check every tank MPG all year around and the extra gas used by the AC in
> the summer is lost in the noise of the MPG readings.

Sorry Matt, but I'm not buying that and I've never heard anyone else
make such a claim. An A/C compressor takes several horspower to run,
which does impact fuel mileage. There is still a debate about whether
rolling down the windows reduces fuel mileage more than using the A/C,
but there is no debate about the fact that either one reduces fuel mileage.

Perhaps you do a lot more city driving than I do, where the mileage drop
is less obvious, but a 3 mpg drop on the highway is normal.

 

Matt Whiting wrote:
> Brian Nystrom wrote:
>
>> Having the A/C compressor running costs me at least 3 mpg in my
>> Elantra. IMO, that's unacceptable for a "feature" that I don't even want.
>
>
> Something is seriously wrong then with your vehicle. I've never seen
> the AC consume even 1 MPG on a modern car. Actually, on my minivans and
> pickup, I can't even tell the difference between using AC and not. I
> check every tank MPG all year around and the extra gas used by the AC in
> the summer is lost in the noise of the MPG readings.

Sorry Matt, but I'm not buying that and I've never heard anyone else
make such a claim. An A/C compressor takes several horspower to run,
which does impact fuel mileage. There is still a debate about whether
rolling down the windows reduces fuel mileage more than using the A/C,
but there is no debate about the fact that either one reduces fuel mileage.

Perhaps you do a lot more city driving than I do, where the mileage drop
is less obvious, but a 3 mpg drop on the highway is normal.

 

JPH wrote:
> Brian Nystrom wrote:
>
>>
>> This same subject was discussed just a few days ago.
>>
>> Untrue. The A/C dries the air, but that not only does no good when
>> you're trying to clear the OUTSIDE of the windshield, it reduces the
>> defroster's effectiveness. If you live up north, it sucks.
>>
>> If you use the defroster to clear the inside of the windshield, then
>> switch to heat once it's clear, the moisture on the condenser coils
>> gets pumped back into the interior of the car and fogs up the windows
>> again. For that reason, I prefer to use heat to clear the windows in
>> the winter.
>>
>> Having the A/C compressor running costs me at least 3 mpg in my
>> Elantra. IMO, that's unacceptable for a "feature" that I don't even want.
>>
>> Unfortunately, this is no longer something that can be easily
>> disconnected. I contacted Hyundai about it when I had a nasty
>> experience with it, but they had nothing to offer. In '04 and up, US
>> market vehicles, the only way to get around this is to splice a switch
>> into the A/C control line that comes out of the heater control module,
>> so you can manually turn the compressor off. It's an inexpensive
>> modification, but it requires removal of the dash facia and a bit of
>> wiring. The switch I used fits where the cigarette lighter was. Since
>> the car has an accessory socket, I didn't mind sacrificing the lighter
>> to get better defroster function.
>
>
> From my understanding, after the temperature drops below a certain
> temperature (usually about 32 degrees) the A/C compressor does not
> switch on in the defrost mode.

That's what I thought too, but you can feel it kick in, both in the drag
that it causes and the difference in the air temp. If it does cut out
completely, it's apparently at a point that's too low, IMO.

 

JPH wrote:
> Brian Nystrom wrote:
>
>>
>> This same subject was discussed just a few days ago.
>>
>> Untrue. The A/C dries the air, but that not only does no good when
>> you're trying to clear the OUTSIDE of the windshield, it reduces the
>> defroster's effectiveness. If you live up north, it sucks.
>>
>> If you use the defroster to clear the inside of the windshield, then
>> switch to heat once it's clear, the moisture on the condenser coils
>> gets pumped back into the interior of the car and fogs up the windows
>> again. For that reason, I prefer to use heat to clear the windows in
>> the winter.
>>
>> Having the A/C compressor running costs me at least 3 mpg in my
>> Elantra. IMO, that's unacceptable for a "feature" that I don't even want.
>>
>> Unfortunately, this is no longer something that can be easily
>> disconnected. I contacted Hyundai about it when I had a nasty
>> experience with it, but they had nothing to offer. In '04 and up, US
>> market vehicles, the only way to get around this is to splice a switch
>> into the A/C control line that comes out of the heater control module,
>> so you can manually turn the compressor off. It's an inexpensive
>> modification, but it requires removal of the dash facia and a bit of
>> wiring. The switch I used fits where the cigarette lighter was. Since
>> the car has an accessory socket, I didn't mind sacrificing the lighter
>> to get better defroster function.
>
>
> From my understanding, after the temperature drops below a certain
> temperature (usually about 32 degrees) the A/C compressor does not
> switch on in the defrost mode.

That's what I thought too, but you can feel it kick in, both in the drag
that it causes and the difference in the air temp. If it does cut out
completely, it's apparently at a point that's too low, IMO.

 

JPH wrote:
> Brian Nystrom wrote:
>
>>
>> This same subject was discussed just a few days ago.
>>
>> Untrue. The A/C dries the air, but that not only does no good when
>> you're trying to clear the OUTSIDE of the windshield, it reduces the
>> defroster's effectiveness. If you live up north, it sucks.
>>
>> If you use the defroster to clear the inside of the windshield, then
>> switch to heat once it's clear, the moisture on the condenser coils
>> gets pumped back into the interior of the car and fogs up the windows
>> again. For that reason, I prefer to use heat to clear the windows in
>> the winter.
>>
>> Having the A/C compressor running costs me at least 3 mpg in my
>> Elantra. IMO, that's unacceptable for a "feature" that I don't even want.
>>
>> Unfortunately, this is no longer something that can be easily
>> disconnected. I contacted Hyundai about it when I had a nasty
>> experience with it, but they had nothing to offer. In '04 and up, US
>> market vehicles, the only way to get around this is to splice a switch
>> into the A/C control line that comes out of the heater control module,
>> so you can manually turn the compressor off. It's an inexpensive
>> modification, but it requires removal of the dash facia and a bit of
>> wiring. The switch I used fits where the cigarette lighter was. Since
>> the car has an accessory socket, I didn't mind sacrificing the lighter
>> to get better defroster function.
>
>
> From my understanding, after the temperature drops below a certain
> temperature (usually about 32 degrees) the A/C compressor does not
> switch on in the defrost mode.

That's what I thought too, but you can feel it kick in, both in the drag
that it causes and the difference in the air temp. If it does cut out
completely, it's apparently at a point that's too low, IMO.

 

Don Allen wrote:
> This "feature" has been in place with most automobiles since the early
> '90s. However, the majority of vehicles disable the AC compressor
> below a certain temperature not only to protect the compressor due to
> low ambient temps, but also not to degrade the defrosting abililty. In
> my 1994 Dodge Grand Caravan ES it disables the compressor when the
> outside ambient temp is below 30 degrees F. The AC light is on when
> the outside temp is below 30 degrees, but the compressor is disengaged.
> I haven't tested this on our new 2006 Elantra, but I would be very
> suprised if this is not the case with Hyundai as well. Otherwise, all
> of us who own Hyundai's will be replacing AC compressors at a rapid
> rate!
>
> Turning on the AC in the defrost mode helps the defogging ability of a
> defroster tremendously by removing the interior humidity.

That's true, but only IF you need it. It's not always necessary.

> Assuming the
> disengagement of the AC compressor at low temps, this is actually very
> good engineering.
>
The devil is in the details. In the Elantra, it doesn't cut out at a
high enough temp to suit me. It definitely adversely affects the
defroster's ability to keep the outside of the windshield free of snow
and ice, especially when the temp is just below the freezing mark.

Additionally, I object to being FORCED to use the defroster this way. I
used to use the A/C combined with the heater or defroster in my ex-wifes
car WHEN I NEEDED IT, but you don't have the option to choose when to
use it in the Elantra. Well, at least you don't in a stock Elantra.
After the modification I made, I can control mine and use it only when
it's beneficial.

 

Don Allen wrote:
> This "feature" has been in place with most automobiles since the early
> '90s. However, the majority of vehicles disable the AC compressor
> below a certain temperature not only to protect the compressor due to
> low ambient temps, but also not to degrade the defrosting abililty. In
> my 1994 Dodge Grand Caravan ES it disables the compressor when the
> outside ambient temp is below 30 degrees F. The AC light is on when
> the outside temp is below 30 degrees, but the compressor is disengaged.
> I haven't tested this on our new 2006 Elantra, but I would be very
> suprised if this is not the case with Hyundai as well. Otherwise, all
> of us who own Hyundai's will be replacing AC compressors at a rapid
> rate!
>
> Turning on the AC in the defrost mode helps the defogging ability of a
> defroster tremendously by removing the interior humidity.

That's true, but only IF you need it. It's not always necessary.

> Assuming the
> disengagement of the AC compressor at low temps, this is actually very
> good engineering.
>
The devil is in the details. In the Elantra, it doesn't cut out at a
high enough temp to suit me. It definitely adversely affects the
defroster's ability to keep the outside of the windshield free of snow
and ice, especially when the temp is just below the freezing mark.

Additionally, I object to being FORCED to use the defroster this way. I
used to use the A/C combined with the heater or defroster in my ex-wifes
car WHEN I NEEDED IT, but you don't have the option to choose when to
use it in the Elantra. Well, at least you don't in a stock Elantra.
After the modification I made, I can control mine and use it only when
it's beneficial.

 

Don Allen wrote:
> This "feature" has been in place with most automobiles since the early
> '90s. However, the majority of vehicles disable the AC compressor
> below a certain temperature not only to protect the compressor due to
> low ambient temps, but also not to degrade the defrosting abililty. In
> my 1994 Dodge Grand Caravan ES it disables the compressor when the
> outside ambient temp is below 30 degrees F. The AC light is on when
> the outside temp is below 30 degrees, but the compressor is disengaged.
> I haven't tested this on our new 2006 Elantra, but I would be very
> suprised if this is not the case with Hyundai as well. Otherwise, all
> of us who own Hyundai's will be replacing AC compressors at a rapid
> rate!
>
> Turning on the AC in the defrost mode helps the defogging ability of a
> defroster tremendously by removing the interior humidity.

That's true, but only IF you need it. It's not always necessary.

> Assuming the
> disengagement of the AC compressor at low temps, this is actually very
> good engineering.
>
The devil is in the details. In the Elantra, it doesn't cut out at a
high enough temp to suit me. It definitely adversely affects the
defroster's ability to keep the outside of the windshield free of snow
and ice, especially when the temp is just below the freezing mark.

Additionally, I object to being FORCED to use the defroster this way. I
used to use the A/C combined with the heater or defroster in my ex-wifes
car WHEN I NEEDED IT, but you don't have the option to choose when to
use it in the Elantra. Well, at least you don't in a stock Elantra.
After the modification I made, I can control mine and use it only when
it's beneficial.

 

cheg wrote:
> *** Update ***
>
>
>>Hello
>
>
>
>>5 years ago I bought an Accent GSi. I got it in the middle of winter,
>
> and I noticed that everytime I turned on the defog mode, the a/c light
> would come on. I got the dealership to disconnect that since I was
> under the impression the a/c compressor sucks a lot of gas.
>
>
>
>>I just picked up my Tuc a few days ago and noticed it does the exact
>
> same thing. Does the a/c thing affect gas consumption when heat is
> blowing out instead of cold air? Can I disconnect this without having
> to go to the dealership? Should I not bother?
>
>
>
>>Thanks for your input
>
>
>
>>Alex
>
>
>
> Unlike my previous car, I found out this morning that I simply had to
> press the a/c to disengage it! On the Accent, you could press all you
> wanted on the a/c switch but it would always be on. Anyway, I'll be
> testing it in the next few days and keep you all informed.

Pressing the A/C button only toggles the light on the button. I has no
effect on the compressor, which remains engaged. That is, unless you're
driving a Canadian-spec car.

 

cheg wrote:
> *** Update ***
>
>
>>Hello
>
>
>
>>5 years ago I bought an Accent GSi. I got it in the middle of winter,
>
> and I noticed that everytime I turned on the defog mode, the a/c light
> would come on. I got the dealership to disconnect that since I was
> under the impression the a/c compressor sucks a lot of gas.
>
>
>
>>I just picked up my Tuc a few days ago and noticed it does the exact
>
> same thing. Does the a/c thing affect gas consumption when heat is
> blowing out instead of cold air? Can I disconnect this without having
> to go to the dealership? Should I not bother?
>
>
>
>>Thanks for your input
>
>
>
>>Alex
>
>
>
> Unlike my previous car, I found out this morning that I simply had to
> press the a/c to disengage it! On the Accent, you could press all you
> wanted on the a/c switch but it would always be on. Anyway, I'll be
> testing it in the next few days and keep you all informed.

Pressing the A/C button only toggles the light on the button. I has no
effect on the compressor, which remains engaged. That is, unless you're
driving a Canadian-spec car.