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

 

cheg wrote:
> 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
>
Leave it alone. The AC dries the air and is part of the defrost system.
Modern cars are mostly economical in the AC systems and do not
use up the fuel like a generation ago.

 

cheg wrote:
> 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
>
Leave it alone. The AC dries the air and is part of the defrost system.
Modern cars are mostly economical in the AC systems and do not
use up the fuel like a generation ago.

 

cheg wrote:
> 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
>
Leave it alone. The AC dries the air and is part of the defrost system.
Modern cars are mostly economical in the AC systems and do not
use up the fuel like a generation ago.

 

James wrote:
> cheg wrote:
>
>> 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
>>
> Leave it alone. The AC dries the air and is part of the defrost system.
> Modern cars are mostly economical in the AC systems and do not
> use up the fuel like a generation ago.

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.

 

James wrote:
> cheg wrote:
>
>> 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
>>
> Leave it alone. The AC dries the air and is part of the defrost system.
> Modern cars are mostly economical in the AC systems and do not
> use up the fuel like a generation ago.

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.

 

James wrote:
> cheg wrote:
>
>> 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
>>
> Leave it alone. The AC dries the air and is part of the defrost system.
> Modern cars are mostly economical in the AC systems and do not
> use up the fuel like a generation ago.

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.

 

cheg wrote:
> 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?

Sure, it affects gas consumption some as it is drawing power from the
engine. However, most modern compressors are pretty efficient. I'd be
surprised if it made 1/2 MPG of difference. And the increased defogging
efficiency is worth it. Hitting something you can't see impacts your
gas mileage a lot more than running the compressor for a few minutes.
And once the windshield is clear, you often get enough defrost airflow
even on the normal heat setting to keep it clear.


Matt

 

cheg wrote:
> 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?

Sure, it affects gas consumption some as it is drawing power from the
engine. However, most modern compressors are pretty efficient. I'd be
surprised if it made 1/2 MPG of difference. And the increased defogging
efficiency is worth it. Hitting something you can't see impacts your
gas mileage a lot more than running the compressor for a few minutes.
And once the windshield is clear, you often get enough defrost airflow
even on the normal heat setting to keep it clear.


Matt

 

cheg wrote:
> 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?

Sure, it affects gas consumption some as it is drawing power from the
engine. However, most modern compressors are pretty efficient. I'd be
surprised if it made 1/2 MPG of difference. And the increased defogging
efficiency is worth it. Hitting something you can't see impacts your
gas mileage a lot more than running the compressor for a few minutes.
And once the windshield is clear, you often get enough defrost airflow
even on the normal heat setting to keep it clear.


Matt

 

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. Assuming the
disengagement of the AC compressor at low temps, this is actually very
good engineering.

 

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. Assuming the
disengagement of the AC compressor at low temps, this is actually very
good engineering.

 

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. Assuming the
disengagement of the AC compressor at low temps, this is actually very
good engineering.

 

*** 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.

Again, thanks for the replies!

Alex

 

*** 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.

Again, thanks for the replies!

Alex