Run Fan Without Activating Climate Control

[DeanM2]

I live in San Diego and rarely need or want to use the AC or heating. I do however, like to have the fan running to circulate some air.
However, whenever I turn on the Fan, it automatically activates the climate control system. And when the climate control system is active, it frequently deactivates the Engine Stop/Start feature, which is a feature I want.

Am I missing something here? How can I run the fan without activating the climate control system???

 

[vincentw56]

I live in San Diego and rarely need or want to use the AC or heating. I do however, like to have the fan running to circulate some air.
However, whenever I turn on the Fan, it automatically activates the climate control system. And when the climate control system is active, it deactivates the Engine Stop/Start feature, which is a feature I want.

Am I missing something here? How can I run the fan without activating the climate control system???

If you turn it off auto on the climate controls (assuming you have it), you can control the fan and temp on your own. The only time auto stop/start is disabled is when AC is on.

 

[HSKR R/T]

I live in San Diego and rarely need or want to use the AC or heating. I do however, like to have the fan running to circulate some air.
However, whenever I turn on the Fan, it automatically activates the climate control system. And when the climate control system is active, it frequently deactivates the Engine Stop/Start feature, which is a feature I want.

Am I missing something here? How can I run the fan without activating the climate control system???

Instead of hitting "auto" just hit the fan speed button. Make sure A/C is off and temp control is all the way cold. Should work like your old "vent" of just bringing in fresh outside air. Or if you set to recirculation, will only blow around the cabin air.

 

[6of36]

I live in San Diego and rarely need or want to use the AC or heating. I do however, like to have the fan running to circulate some air.
However, whenever I turn on the Fan, it automatically activates the climate control system. And when the climate control system is active, it frequently deactivates the Engine Stop/Start feature, which is a feature I want.

Am I missing something here? How can I run the fan without activating the climate control system???

The engine should still start stop, unless the cabin temp is a few degrees off of the set temp. Even then, it should shut off when temp is reached, then re start, if you sit long enough that the temp changes a few degrees. Comfort level overrides the start stop, but it still works.

 

[BowDown]

If you turn it off auto on the climate controls (assuming you have it), you can control the fan and temp on your own. The only time auto stop/start is disabled is when AC is on.

That's no longer correct. If you have the latest HVAC updates, auto start/stop will not engage with just the fan on. I've seen that usually the interior temp needs to be within 12° of outside for auto start/stop engages on mine now. I believe that's the issue the OP is facing. I regularly get auto start/stop unavailable due to cabin heating or cooling with just the fan on

 

[6of36]

That's no longer correct. If you have the latest HVAC updates, auto start/stop will not engage with just the fan on. I've seen that usually the interior temp needs to be within 12° of outside for auto start/stop engages on mine now. I believe that's the issue the OP is facing

Agreed. It only keeps running, if the truck is too far from set temperature, and is trying to reach it. If the setting is near the cab temperature, the start stop will function.

 

[BowDown]

I honestly don't like the newest update, I liked the way mine (AS/S) worked in the past, I'd like the new HVAC TSB ,because it does cool much better, with the old HVAC programming. I have lost a solid 1mpg now that AS/S doesn't engage as often or at all esp. in the summer. I have gotten it to engage more now that temps aren't 2000°

The new HVAC hardware update is great and a vast improvement but the programming could be better

 

[DeanM2]

That's no longer correct. If you have the latest HVAC updates, auto start/stop will not engage with just the fan on. I've seen that usually the interior temp needs to be within 12° of outside for auto start/stop engages on mine now.

Yes, your statement is correct. I have not tested it yet, but I am pretty sure that the set temp has to be much closer to the outside temperature than 12 degrees. If I am even 3-4 degrees off, then the Start/Stop does not work.

Guess this is just another example of Ram's inability to properly program software.

 

[BowDown]

Yes, your statement is correct. I have not tested it yet, but I am pretty sure that the set temp has to be much closer to the outside temperature than 12 degrees. If I am even 3-4 degrees off, then the Start/Stop does not work.

Guess this is just another example of Ram's inability to properly program software.

It varies, humidity may play a role too. I've seen it work as you described, as little as a few degrees as well as 12° apart which seems to be the limit. I think they, Ram, went too aggressive with the programming because of the initial complaints on the 19-20 trucks. I know there's been 2 or 3 iterations of the HVAC upgrades. Mine has the latest and I believe its the HVAC controller that doing this

 

[Cbty2050]

It varies, humidity may play a role too. I've seen it work as you described, as little as a few degrees as well as 12° apart which seems to be the limit. I think they, Ram, went too aggressive with the programming because of the initial complaints on the 19-20 trucks. I know there's been 2 or 3 iterations of the HVAC upgrades. Mine has the latest and I believe its the HVAC controller that doing this

You are claiming stop start will not work when the cabin temp vs exterior temp difference is more than 12 degrees?

I don't know of any car that allows a fan only mode for the hvac. I could be wrong.

 

[BowDown]

You are claiming stop start will not work when the cabin temp vs exterior temp difference is more than 12 degrees?

I don't know of any car that allows a fan only mode for the hvac. I could be wrong.

Below is just with the fan on, no AC. I believe this is what the OP was referring to when he says fan mode. I've been able to operate the fan alone without the AC being on in all my cars.


12° difference inside vs outside





Once I stopped


13° difference inside vs outside





I cannot say for fact that its a 12° delta but my simple testing of this has repeatedly and consistently yielded the same results in regards to the temp delta & AS/S.

 

[Cbty2050]

Below is just with the fan on, no AC. I believe this is what the OP was referring to when he says fan mode. I've been able to operate the fan alone without the AC being on in all my cars.


12° difference inside vs outside

View attachment 169962

View attachment 169963

Once I stopped
View attachment 169961

13° difference inside vs outside

View attachment 169964

View attachment 169966

I cannot say for fact that its a 12° delta but my simple testing of this has repeatedly and consistently yielded the same results in regards to the temp delta & AS/S.

The truck will not stop start ever if you stay at 68 interior vs 81 and up exterior? Will it stop start operate after the hvac system gets cabin to set temp?

 

[BowDown]

The truck will not stop start ever if you stay at 68 interior vs 81 and up exterior? Will it stop start operate after the hvac system gets cabin to set temp?

AS/S will not engage (shows not ready cabin heating/cooling) any time the delta is greater than 12° between inside and outside. <12° delta and it functions normally unless AC is on in which case it never shows ready or engages. IDK on set temp, in the summer, I leave it on low. The AC TSB is 24-013-21 was just preformed in late July so I haven't tried any cold weather testing with a set temp.

AS/S not engaging in the TX summer doesn't really bother me, I understand why it doesn't and the change was made, the cabin heated up quick when AS/S engaged during 100°+ weather.
I'm hoping it's less aggressive in cold weather

 

[DeanM2]

I cannot say for fact that its a 12° delta but my simple testing of this has repeatedly and consistently yielded the same results in regards to the temp delta & AS/S.

Tested mine again, today. What I found is that the external temperature reading is not what is used. It seems to use cabin temperature (which has no readout) Vs. Comfort set point. If my cabin temperature (not the outside temperature) is more than a few degrees away from the comfort set point, the Start/Stop screen shows "Not Ready. Cabin Cooling or Heating". And since the AC is not "on", only the fan, it will never be able to cool it off enough to re-enable the start/stop.
@RamCares This is REALLY STUPID! I want to increase my MPG by not using the AC and using start/stop, but also just run the fan!!! But this damn truck will not let me!

 

[Cbty2050]

Tested mine again, today. What I found is that the external temperature reading is not what is used. It seems to use cabin temperature (which has no readout) Vs. Comfort set point. If my cabin temperature (not the outside temperature) is more than a few degrees away from the comfort set point, the Start/Stop screen shows "Not Ready. Cabin Cooling or Heating". And since the AC is not "on", only the fan, it will never be able to cool it off enough to re-enable the start/stop.
@RamCares This is REALLY STUPID! I want to increase my MPG by not using the AC and using start/stop, but also just run the fan!!! But this damn truck will not let me!

Now you are reaching, you want better MPG with oversized tires and a level? Stop, you can't

 

[BowDown]

Tested mine again, today. What I found is that the external temperature reading is not what is used. It seems to use cabin temperature (which has no readout) Vs. Comfort set point. If my cabin temperature (not the outside temperature) is more than a few degrees away from the comfort set point, the Start/Stop screen shows "Not Ready. Cabin Cooling or Heating". And since the AC is not "on", only the fan, it will never be able to cool it off enough to re-enable the start/stop.
@RamCares This is REALLY STUPID! I want to increase my MPG by not using the AC and using start/stop, but also just run the fan!!! But this damn truck will not let me!

How are you determining that if you don't know what the actual cabin temp is and there's no cabin temp displayed?

I agree with Cbty2050 on the mileage comment, you cant really make those kinda changes that are 100% detrimental to fuel savings then complain about AS/S operation. The wheel/tire change alone likely cost you 2-3 mpg

 

[HSKR R/T]

How are you determining that if you don't know what the actual cabin temp is and there's no cabin temp displayed?

I agree with Cbty2050 on the mileage comment, you cant really make those kinda changes that are 100% detrimental to fuel savings then complain about AS/S operation. The wheel/tire change alone likely cost you 2-3 mpg

People can modify their vehicles to be what they want and still be concerned about maximizing the mileage for their vehicle. I've definitely killed my mileage with my mods, but on longer trips, still try to get the best mileage I can.

 

[BowDown]

People can modify their vehicles to be what they want and still be concerned about maximizing the mileage for their vehicle. I've definitely killed my mileage with my mods, but on longer trips, still try to get the best mileage I can.

I'm no astro physicist but those two actions seem to be not complementary to one another. There's a difference between wanting the best mileage you can get and wanting to "increase my MPG" while making changes that do the exact opposite. That said, I do get his point about AS/S and fuel mileage which despite what many here think, AS/S does improve fuel mileage.

 

[DeanM2]

How are you determining that if you don't know what the actual cabin temp is and there's no cabin temp displayed?

I set the Comfort set point to the exact same value as the outside temperature. And I still get the "Not Ready. Cabin Cooling or Heating" because the truck has been sitting in the Sun, and the interior is much hotter than the outside temperature. If I set the Comfort temperature to my best guess as to the truck inside temperature, then I can get the Start/stop to work.

I just want to be able to use the fan without impacting the start/stop.

 

[DeanM2]

I'm no astro physicist but those two actions seem to be not complementary to one another.

They are absolutely not complementary to one another, as you correctly stated! But as you said, you are neither an Astro Physicist... or an Engineer.
It is a concept known as "trade offs", used in all design, maintenance, and life decisions. I am willing to give up MPG to have bigger tires, but I am not willing to give up MPG to run, ONLY, the fan.