Dodge Challenger Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
218 Posts
Discussion Starter #1
I've noticed that even with the AC off on the console switch, the compressor will some times be on even if it is 30deg out and 30% humidity. There is no reason for the AC to be coming on under those conditions. Is there a way to turn it off unless I want it on?
 

·
Registered
Joined
·
1,550 Posts
I've noticed that even with the AC off on the console switch, the compressor will some times be on even if it is 30deg out and 30% humidity. There is no reason for the AC to be coming on under those conditions. Is there a way to turn it off unless I want it on?
Run the system in Manual and don't use the defrosters once the window is defrosted.
 

·
Registered
Joined
·
2,272 Posts
I've noticed that even with the AC off on the console switch, the compressor will some times be on even if it is 30deg out and 30% humidity. There is no reason for the AC to be coming on under those conditions. Is there a way to turn it off unless I want it on?
That's kind of strange. With other cars my experience is the A/C compressor is not turned on even if the A/C system is turned on if the air temperature is below freezing. This is to prevent ice from forming on the A/C evaporator and possibly blocking air flow through it.

So far, and it is unlikely unless I venture to colder climes, my Challenger has not been exposed to freezing temperatures so I don't know what the behavior will be.

Just occurred to me that maybe in the case of your car that the A/C compressor is on then off some times is another way of dealing with the possibility of the evaporator freezing up?

If you can it is always a good idea to run the A/C system, including the compressor, once in a while even in the winter. This exercises the compressor, circulates refrigerant and oil through the system, all of which helps preserve the various seals (mainly o-rings) that help the system retain the refrigerant and oil under considerable pressure. And if the A/C compressor is on and it is time to turn the A/C system off it is a good idea to first turn off the compressor while the cabin ventilation fan runs, to "dry" out the evaporator and the air ducts. This helps the system from developing a moldy/mildewy smell. Parking the car with A/C system "damp" can encourage mold/mildew growth on various surfaces and once this stuff takes root (so to speak) it is very hard to get rid of. I turn off the compressor a few minutes from my final destination to give the system time to dry.

In the winter I run my A/C system in "auto" mode with the A/C compressor turned off. This works well most of the time. But occasionally, like when in a rain storm -- last night on the way home as a matter of fact -- and the windows start to fog up, I have to turn on the A/C to dry the windows.
 

·
Registered
Joined
·
14,292 Posts
True on running the compressor, it's good for it to run at least occasionally year round. The owners manual even says before winter storage to run you a/c compressor for 5 minutes before putting the car away.


Sent from my SM-N920T using Tapatalk
 

·
Super Moderator
Joined
·
15,397 Posts
below a given low temperature threshold, the a/c compressor will not operate to protect it.

Like others mentioned you switch to manual mode (set fan speed manually vs. AUTO) and you have to not use vent positions that are Floor, Defrost.

A blend between Floor / Windshield will switch the a/c to allow it to cycle as needed for keeping windows clear of fogging
 

·
Super Moderator
Joined
·
15,397 Posts
System is set to manual, vents always are on floor/dash. It still turns itself on when it wants to...
Set them to vent positons - if you have floor (or any combo w/ floor) it will turn a/c compressor on.

I've tried various settings and found - Panel (vent) or Bi-Level are the postions that allow manual HVAC w/o the a/c compressor.

any other position- Floor, Mix, Defrost will have a/c compressor still cycle intermittently.

from the manual:

For Manual Climate Controls, if the system is in Mix,
Floor or Defrost Mode, the A/C can be turned off, but
the A/C system shall remain active to prevent fogging
of the windows
 

·
Registered
Joined
·
193 Posts
Perfectly normal and all cars and trucks have done it for the last 30+ years as a way of evaporating moisture out of the interior while running the defrost/defogger setting as long as everything is working properly as designed from the factory. Really no way to turn it off if you have the HVAC set in any defrost function. Not sure why you are so determined to have it off when it's doing what it's designed to do. Running the compressor at frequent intervals is what keeps them going for a long time. There is oil in the refrigerant which keeps the parts and seals lubricated. If you really must have it off you could always disconnect the wiring harness from the compressor.
 

·
Registered
Joined
·
408 Posts
Per the manual, you want it to run so your bearing doesn't dry out.
 

·
Premium Member
Joined
·
1,434 Posts
No dries out seals
 

·
Registered
Joined
·
8 Posts
I've noticed that even with the AC off on the console switch, the compressor will some times be on even if it is 30deg out and 30% humidity. There is no reason for the AC to be coming on under those conditions. Is there a way to turn it off unless I want it on?
the A/C DRIES THE DEFROSTER AIR BEFORE IT HITS THE WINDSHIELD , SHUTTING DOWN THE COMPRESSOR WILL CAUSE FOGGED WINDSHIELD , INSTEAD OF CLEAR VIEW IN WINTER OR HIGH HUMIDITY DAYS (SORRY CAPS FROZEN , NOT YELLING , TYPING FOR THE HEARING IMPAIRED)
 

·
Registered
Challenger SXT
Joined
·
44 Posts
I also want to be able to run the HVAC with the compressor off and air blowing through the A/C evaporator.

In this part of the country, it is common for the evaporator to get a lot of awful/stinky stuff growing in it if you shut the car off with the evaporator soaked from drying out the air.

What I do is shut off the compressor and let the dried inside air blow through it for the last couple of miles before I get home. This makes the inside of the car a little muggy for the last minute or two before pulling into the garage but it is quite effective in reducing the amount of mold growing in the evaporator.

Sometimes when it is cold (and it has been COLD here lately), the compressor comes on when I don't want it to. All I want to do is to run air through the evaporator for a couple minutes before I park the car so as to reduce the amount of moisture.

What settings do I use to run air through the system with the compressor off? ..... manual number for fan, blow through dash only, select compressor off, select inside air ????
 

·
Registered
Joined
·
1,550 Posts
Perfectly normal and all cars and trucks have done it for the last 30+ years as a way of evaporating moisture out of the interior while running the defrost/defogger setting as long as everything is working properly as designed from the factory. Really no way to turn it off if you have the HVAC set in any defrost function. Not sure why you are so determined to have it off when it's doing what it's designed to do. Running the compressor at frequent intervals is what keeps them going for a long time. There is oil in the refrigerant which keeps the parts and seals lubricated. If you really must have it off you could always disconnect the wiring harness from the compressor.
I do this too, sometimes, on a 70 degree day, when the A/C "Auto" wants to run the compressor and send me cool air, and all I want is fresh outdoor air. I simply take it off of Auto (place it in one of the other settings, except for "Defrost") and if the A/C light comes on, press it to turn it off. The location that you blow the air is not relevent (windshield, feet, dashboard), just so long as the A/C is off and you do not select "Defrost" On my 2013, Defrost has a picture of what looks like the windshield, with some squiggly lines in it. Damn, I miss the old days when the defrost setting actually had the word "DEFROST".
 

·
Super Moderator
Joined
·
15,397 Posts
I also want to be able to run the HVAC with the compressor off and air blowing through the A/C evaporator.

In this part of the country, it is common for the evaporator to get a lot of awful/stinky stuff growing in it if you shut the car off with the evaporator soaked from drying out the air.

What I do is shut off the compressor and let the dried inside air blow through it for the last couple of miles before I get home. This makes the inside of the car a little muggy for the last minute or two before pulling into the garage but it is quite effective in reducing the amount of mold growing in the evaporator.

Sometimes when it is cold (and it has been COLD here lately), the compressor comes on when I don't want it to. All I want to do is to run air through the evaporator for a couple minutes before I park the car so as to reduce the amount of moisture.

What settings do I use to run air through the system with the compressor off? ..... manual number for fan, blow through dash only, select compressor off, select inside air ????
For '08 - '14:
>Set to Vent position

>Push A/C switch (snowflake icon) Off (not illuminated)

>Run fan on High or higher settings to blow unconditioned air through evaporator /heater core to dry out condensation and force any accumulated condensate out evap box drain

For '15+:
>Set to Vent position

>Run fan on High or higher settings to blow unconditioned air through evaporator /heater core to dry out condensation and force any accumulated condensate out evap box drain

>Push A/C switch Off (not illuminated in case it switched On when changing settings)
Run fan on High or higher settings to blow unconditioned air through evaporator /heater core to dry out condensation and force any accumulated condensate out evap box drain

I've done these steps in the Summer months - since I might only use the Challenger or my other car less (weekend warrior) and want to dry the evaporator out - don't have the window fogging on next use or that musty smell.

I've done this on both the former '09 and my '16 as well as other cars that have Auto climate control

On Challengers - any position that is Floor, Blend, Defog (windshield) will trigger A/C compressor to cycle intermittently. So you have to use Vent or Bi-Level to avoid that compressor to operate.
 

·
Registered
Joined
·
1,550 Posts
For '08 - '14:
>Set to Vent position

>Push A/C switch (snowflake icon) Off (not illuminated)

>Run fan on High or higher settings to blow unconditioned air through evaporator /heater core to dry out condensation and force any accumulated condensate out evap box drain

For '15+:
>Set to Vent position

>Run fan on High or higher settings to blow unconditioned air through evaporator /heater core to dry out condensation and force any accumulated condensate out evap box drain

>Push A/C switch Off (not illuminated in case it switched On when changing settings)
Run fan on High or higher settings to blow unconditioned air through evaporator /heater core to dry out condensation and force any accumulated condensate out evap box drain

I've done these steps in the Summer months - since I might only use the Challenger or my other car less (weekend warrior) and want to dry the evaporator out - don't have the window fogging on next use or that musty smell.

I've done this on both the former '09 and my '16 as well as other cars that have Auto climate control

On Challengers - any position that is Floor, Blend, Defog (windshield) will trigger A/C compressor to cycle intermittently. So you have to use Vent or Bi-Level to avoid that compressor to operate.
That was much better than my "avoid the one with the sqiggly lines" explanation.
 

·
Registered
Joined
·
8 Posts
That was much better than my "avoid the one with the sqiggly lines" explanation.
The quick design of safety in driving is the primary reason , but being on the subject , buy a can of Lysol spray to kill mold in evaporator from trapped moisture , with A/C on medium fan spray Lysol into air intake , the dealer sells cans relabeled for big bucks , Walmart or any grocery or department store sell cheap , mold can cause athzma attacks with serious consequences the squiggly lines button is for electric defrosters in side view mirrors and back window ,
 

·
Registered
Joined
·
1,550 Posts
The quick design of safety in driving is the primary reason , but being on the subject , buy a can of Lysol spray to kill mold in evaporator from trapped moisture , with A/C on medium fan spray Lysol into air intake , the dealer sells cans relabeled for big bucks , Walmart or any grocery or department store sell cheap , mold can cause athzma attacks with serious consequences the squiggly lines button is for electric defrosters in side view mirrors and back window ,
Damn squiggly lines. I just press them and everything looks good in a few minutes.

And don't forget the cabin air filter. I forgot about mine for 5 years. Came to me out of the blue. When I pulled it out, it looked like Newark, N.J......on a good day.
 
1 - 20 of 30 Posts
Top