How to Add Automatic Temperature Control (ATC) to a Manual Temperature Control Truck

[clifford15]

why doesn't it require it in the 2500 is it because it has it already and if so where would said sensor be found

The HD trucks do no use a variable displacement AC compressor like the 1500s. It’s either on or off by the clutch.

 

[RadRam1500]

Hello,

I am new to the forum. I am really enjoying the flexibility of being able to customize so much. I have a 2018 Ram 1500 Express. I am struggling with finding the HVAC module. Does anyone know if it is in the same location as past 4th gens? The 24 pin connector behind the radio seems to have a wire in PIN 12.

 

[crash68]

I have a 2018 Ram 1500 Express. I am struggling with finding the HVAC module. Does anyone know if it is in the same location as past 4th gens? The 24 pin connector behind the radio seems to have a wire in PIN 12.

The HVAC module is on the right side of the passenger footwell area. Pull the lower glovebox to access it.
Pics of where it's at:
https://www.ramforum.com/threads/2014-1500-climate-control-wont-turn-on.88739/#post-1341497

 

[RadRam1500]

Thanks, I will open up the footwell area and take a look. I had the side panel by the door open as well as my upper glove box, but I did not see it.

 

[Ricks Ram]

Hello,

I am new to the forum. I am really enjoying the flexibility of being able to customize so much. I have a 2018 Ram 1500 Express. I am struggling with finding the HVAC module. Does anyone know if it is in the same location as past 4th gens? The 24 pin connector behind the radio seems to have a wire in PIN 12.

If your truck came with the RA1 or RA2 3" and 5" radio the heater control module is integrated in the actual climate control buttons. The trucks that come from the factory with the RA3 or RA4 8" radio have a heater control module mounted separately from the actual bezel. It is located on the right side of the dash on the right side of the glovebox. You can access it by removing the trim piece in the end of the dash.I am only mentioning this because most Express trucks are equipped with the smaller RA1 and RA2 radios that don't have a separate heater control module and that may be why you can't find it.

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[RadRam1500]

If your truck came with the RA1 or RA2 3" and 5" radio the heater control module is integrated in the actual climate control buttons. The trucks that come from the factory with the RA3 or RA4 8" radio have a heater control module mounted separately from the actual bezel. It is located on the right side of the dash on the right side of the glovebox. You can access it by removing the trim piece in the end of the dash.I am only mentioning this because most Express trucks are equipped with the smaller RA1 and RA2 radios that don't have a separate heater control module and that may be why you can't find it.

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Yes that would explain why I cannot find it! So how can I get the atc working? Can I use the integrated manual one (and put behind the atc controls) and change the wires going to it? I also don't know where I can put the 2 in cabin sensor wires.

 

[misfit77]

I don't have issues with temp control...heck my other car has it and I find myself changing manually anyway.

I want to see a write up on how to make these dam Mopar ACs colder.

 

[Mpgrimm2]

Yes that would explain why I cannot find it! So how can I get the atc working? Can I use the integrated manual one (and put behind the atc controls) and change the wires going to it? I also don't know where I can put the 2 in cabin sensor wires.

You can't install ATC without the 8.4 radio conversion is to have the RA1/Ra2. If you do, to will also want to get a 2018/19 classic UAQ or UAS radio to avoid issues with the 8.4 upgrade in your 2018 truck.

M² Mods.

 

[RadRam1500]

Yes, I did the 8.4 UAQ upgrade already with a 8.4 dual zone atc bezel. This is a great forum and I learned alot so far.

The 5 wires, Ignition, CanHi, CanLo, gnd, and hazard, have been connected to the 8 pin of the atc. Confirmed that volume, hazard, screen off buttons all work. Now I will shift about 8 wires of the 24 pin connector in order to match the pinout of the new 2018 hvac module, since my express did not come with the separate module. Also, I will connect the 2 wires for the in cabin temperature sensor.

Lastly, will use alfaobd to configure the atc.

I think this should work. Fingers crossed.

 

[RadRam1500]

I almost got this to work. The 2018 module is working as the AUTO setting is changing the fan speed and blower location (ie floor vs windshield). But I am only getting hot air regardless of the temperature setting. Even in manual with the A/C on.

There are 2 pins for the temp actuator, 3 and 6 for driver and passenger. I assumed that the pin 3 (passenger) is not needed, so I am using pin 6. I have to recheck that connection I think. Please let me know if this sounds right.

 

[Ricks Ram]

I almost got this to work. The 2018 module is working as the AUTO setting is changing the fan speed and blower location (ie floor vs windshield). But I am only getting hot air regardless of the temperature setting. Even in manual with the A/C on.

There are 2 pins for the temp actuator, 3 and 6 for driver and passenger. I assumed that the pin 3 (passenger) is not needed, so I am using pin 6. I have to recheck that connection I think. Please let me know if this sounds right.

If you are installing the ATC (Automatic Temperature Control) you will need to run a humidity sensor as well as the interior temp sensor in order for the system to work properly. Without the humidity sensor the compressor will run whenever you are using the climate control in either manual or automatic mode even if you are just using the vent. When you enabled the ATC code did you first enable the dual zone auto control and then switch it to single zone auto temp control?

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[RadRam1500]

Good news, it was pin 6 not making a good connection. It works great now. Rick, I will be installing the humidity sensor this weekend, once my new mirror arrives. Thank you so much for all of your help. I would have still been looking for my module.

 

[Mpgrimm2]

Got your cable thanks much , installed programmed to dual atc , right now I can’t change the up or down for hot or cold and no temp display on screen yet .
When you say set to auto atc then wait “ does this take a while like maybe over night “ ?
Thanks


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For @Jordanp from the 8.4 Upgrade thread,

From the AlfaOBD Thread OP for " Known working codes" Link...

(Connect to BCM -> go to "raised hood" icon -> Car Configuration Change )

Vehicle Configuration 3: HVAC Configuration:
Select:
Dual Zone ATC

Disconnect AlfaOBD app & shut off the truck for a few minutes and you must wait for the Dual Temp sliders to display on the 8.4 radio before proceeding with single zone ATC change.

(Battery disconnect or pulling the 20A inline radio fuse near the brake booster ... between these changes can speed up the radio/BCM reset for changes, especially with a UAQ/UAS radio (think 15-30mins). * Radio is not reset until XM button displays again and/or Backup Cam works if installed)

Select:
Single Zone ATC

NOTE: your original config would be "Single Zone MTC"

Additional how to videos by @big daddys house
AlfaOBD: Full Video Tutorals (Step By Step)

 

[Jordanp]

For @Jordanp from the 8.4 Upgrade thread,

From the AlfaOBD Thread OP for " Known working codes" Link...

(Connect to BCM -> go to "raised hood" icon -> Car Configuration Change )

Vehicle Configuration 3: HVAC Configuration:
Select:
Dual Zone ATC

Disconnect AlfaOBD app & shut off the truck for a few minutes and you must wait for the Dual Temp sliders to display on the 8.4 radio before proceeding with single zone ATC change.

(Battery disconnect or pulling the 20A inline radio fuse near the brake booster ... between these changes can speed up the radio/BCM reset for changes, especially with a UAQ/UAS radio (think 15-30mins). * Radio is not reset until XM button displays again and/or Backup Cam works if installed)

Select:
Single Zone ATC

NOTE: your original config would be "Single Zone MTC"

Additional how to videos by @big daddys house
AlfaOBD: Full Video Tutorals (Step By Step)

Ok so this morning when I got in truck after setting last night dual zone atc I see the single zone slider with the temp . Should I just leave it or go ahead now and change to single ?


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[Jordanp]

Ok so this morning when I got in truck after setting last night dual zone atc I see the single zone slider with the temp . Should I just leave it or go ahead now and change to single ?


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Everything is working fine , thanks [emoji120]


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[ps2012st]

Some help please....So after installing everything, modules, sensors, UA radio, carplay module..harnesses etc to obtain the Single zone ATC..I was able to get the single slider after going to the double slider first, but it was either all hot or all cold, nothing in between. I did enable the humidity and temp sensors, and then somehow I was now getting a 185 degree outside temp reading. I turned them off today and went back to manual single zone.....after restart I have dual zone sliders that don't move on the radio screen, but manual control on the HVAC controls that now moves in increments up and down for heating and cooling. Check engine light is off....still 185 outside.

Have to take this beast in for service and would love to get this resolved before pulling out the harness. My bad on the Alpha is that I didn't write down the config. the only other thing I changed was from Ram 1500 to Bighorn to try and get the splash screen on my upgraded cluster to change. No luck there either. Anyone else with similar problems? Thanks guys

 

[crash68]

Some help please....So after installing everything, modules, sensors, UA radio, carplay module..harnesses etc to obtain the Single zone ATC..I was able to get the single slider after going to the double slider first, but it was either all hot or all cold, nothing in between. I did enable the humidity and temp sensors, and then somehow I was now getting a 185 degree outside temp reading. I turned them off today and went back to manual single zone.....after restart I have dual zone sliders that don't move on the radio screen, but manual control on the HVAC controls that now moves in increments up and down for heating and cooling. Check engine light is off....still 185 outside.

You should not have had to add/turn on any of the sensors. Once you enable the Dual Zone wait till the dual sliders show up then change it to Single zone. If it doesn't work right away, you may have to drive it around a little (a couple drive cycles) for it to fully kick in. Some have had options show up a couple hours or the next day.
If you can't remember what options you changed that effected the outside temperature, you may have to pull everything out and see if the dealer will flash it back to stock.

 

[ps2012st]

Thanks Crash...I actually got it to a Single Zone slider, but there was no temp variation...just all hot or all cold....that's what made me try and switch it back....now I just have other problems. You may be right on the dealer visit....when you say pull everything out do you mean the radio and HVAC panels as well as all the harnesses I have installed?

 

[crash68]

When ATC is works more by varying the blower speed than the temperature coming out of the vents/floor. It's possible there is a problem with the HVAC module?
Sounds like you did a radio upgrade also, if you want the dealer to put it back to stock yes it should be completely stock.

 

[Ricks Ram]

Some help please....So after installing everything, modules, sensors, UA radio, carplay module..harnesses etc to obtain the Single zone ATC..I was able to get the single slider after going to the double slider first, but it was either all hot or all cold, nothing in between. I did enable the humidity and temp sensors, and then somehow I was now getting a 185 degree outside temp reading. I turned them off today and went back to manual single zone.....after restart I have dual zone sliders that don't move on the radio screen, but manual control on the HVAC controls that now moves in increments up and down for heating and cooling. Check engine light is off....still 185 outside.

Have to take this beast in for service and would love to get this resolved before pulling out the harness. My bad on the Alpha is that I didn't write down the config. the only other thing I changed was from Ram 1500 to Bighorn to try and get the splash screen on my upgraded cluster to change. No luck there either. Anyone else with similar problems? Thanks guys

The cluster needs to be one of the newer ones in order to show a different boot up screen other than the Ram emblem. I believe it's the 16 and newer but it could be the 15 and newer. I'm not positive which. As far as the outside temp showing °185 there is definitely something that got changed. The outside temp is read from your drivers mirror. The usual default temp if it's not reading the mirror sensor is -40. I have never seen 185 display as any type of default temp so not quite sure what's going on there. As Crash69 stated it's usually better to put it all back to stock before you have a dealer flash the truck so you can start over fresh and so they don't give you any grief about the changes you have made. Since it is such minimal effort to switch the radio and bezel you may want to just put it all back. I have had mine flashed twice after I did the 8.4 upgrade and didnt have any issues. It h
Just changed my 8.4 setup back to Single Zone MTC. I knew the tech and he knew all the mods I had done so I didn't bother putting it back to stock. Once it's flashed back to stock don't enable the humidity sensor ect. Others have done the same thing and had similar issues. For some reason the trucks don't like it. Once its all back to normal try setting the ATC again. Go Dual Zone and wait for it to take. Don't mess with it or try to change temps. Just wait for it to show up which can take a while with those radios and then switch it to Single Zone and give it several on off cycles and time to change. Once it takes the Single Zone code give it a try and see what it does. If it's still acting up I would lean towards the heater control module as stated. Make sure you have the correct one and change it to see if it corrects your issue. You can also use the Alfa tool to check for DTC codes in the HVAC system. Remember if you want the dealer to flash the truck you will need to tell them too. Also remember any other codes you have previously enabled will be disabled and need to be reset.

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