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

load97 said:

Thanks for quick response. I posted a question in the HVAC problem thread as well. Here's what I have going (read below).

I noticed the the last two mornings something odd going on. FYI it is around -5*F out last few mornings this occurs.

Before I shut the truck off for the night when I get home, I make sure the truck is in auto climate control set at 74*F. In the morning I remote start the truck (Drone Mobile). After it's running 10 min (when I get in the truck roughly as I'm getting ready for work prior 10 min), I notice the climate control shows it's heating the floor only. I put my hand up by the defrost and there's slight amount of residual air flow. That's about it. So the window starts to fog up a bit. I manually hit the combo defrost/floor blend and it does as it should, but now it's not in auto. This has happened both mornings to work and when leaving work with about same temps outside. I was wondering if there is a setting to change in Alpha OBD for what defaults to for winter or summer? I also wondered about putting my 2015 HVAC module back in? After installing the ATC harness on Wednesday I didn't notice this behavior, but It was pretty cold out lol when installing everything. Any suggestions?

FYI - On my 2019 Jeep Cherokee it's always is defrost or a blend of defrost/floor (forget which) when started when cold outside.

Click to expand...

When you have the truck on Auto it shouldn't show you were the air is flowing. It should just show an (A) on the climate icon and if you go into the climate screen they should all be grayed out until you take it off Auto similar to your Jeep. Did your truck come with the 8.4 radio and if so why did you replace your HVAC module? There is no setting we have found to change the parameters that control the air flow. I know for sure my truck is on defrost/floor when I remote start my truck on cold mornings. It may have been on full defrost a few times but to be honest I've never really gone back in and checked to see. I am definitely going to check it now just to see how it acts. The one thing I have noticed is the climate control does not really start blowing until the engine temperature reaches a point to actually do some good instead of just blowing cold air. I have noticed with this mod the ATC works but I doubt it works as good as a factory dual zone ATC set up because we are running our trucks on ATC when the HVAC system wasn't really designed for it. All that being said if your truck never goes on any type of Defrost on ATC then I think there is definitely something strange going on. I am assuming it acts the same if you start the truck with a key when you have it on ATC on a cold morning?

Sent from my SM-G960U using Tapatalk

I have to do some running around at lunchtime for work today. I will go freeze my butt LOL and start it manually and see what it does.

I’m pretty sure when I set it to auto the floor heat icon appears (lit) on the 8.4 4C screen. I switched out HVAC module to 2018 model because of the radio and the heater controls not working correctly.

@load97 I did activate the humidity sensor in my Ram under LIN and Misc - Humidity Sensor Present. However, as @Ricks Ram has stated some have had issues. While I did not have any issues doing so, I observed no change in activating it through Alfa. As stated, the BCM automatically picks the sensor up and resolves the AC compressor not shutting off issue.

As far as the auto setting. I have tested this in my truck and noticed there is a blend of floor and defrost in cold conditions. When the truck starts to warm, it appears as though it switches to mostly floor. Just yesterday here in VA after the rains and it warmed up, mine (set at 70) actually switched from heat at floor to a very slight cool at the vent.

load97 said:

I have to do some running around at lunchtime for work today. I will go freeze my butt LOL and start it manually and see what it does.

I’m pretty sure when I set it to auto the floor heat icon appears (lit) on the 8.4 4C screen. I switched out HVAC module to 2018 model because of the radio and the heater controls not working correctly.

Click to expand...

Ok. When it's actually on Auto it shouldn't show where the air flow is going. It should all be grayed out in the climate screen and have an (A) in the heater control soft key and it should definitely go into defrost mode when needed. I am assuming your truck is a 15 and you installed a 2018 UAQ or UAS radio? Sorry if you had already stated that somewhere but I can't see certain things with Taptalk. I actually installed the 2018 UAQ radio in my truck for a brief time but did not like it and took it back out and put my RA4 back in. Unfortunately it was during the summer and I didn't leave it in long enough to see it if it had any issues with ATC. I did not like the way it couldn't communicate certain things to the EVIC and the truck and just didn't care for the themes or the over all look of it. That being said STecoD Actually has a 2015 Eco diesel and he has the 2018 UAQ radio and he has the ATC mod. He lives around the corner from me. I will shoot him a text and ask him to check and see how to his acts since he's basically running the same setup as you are. I'm pretty sure he would have noticed by now if his defrost wasn't working but I'll double check.

Sent from my SM-G960U using Tapatalk

Thanks. I’ll report back my finding. You are correct with my vehicle and radio swap (done through infotainment.com)

load97 said:

Thanks. I’ll report back my finding. You are correct with my vehicle and radio swap (done through infotainment.com)

Click to expand...

Ok he sent me a picture of his screen and it acts the same as the RA4. You cannot see the air flow setting or fan speed when it's on Auto. He said he hasn't noticed it not going to defrost but since his truck is the Eco diesel when he gets in the truck it he just turns it to full defrost because it takes so long to warm up anyway.

Sent from my SM-G960U using Tapatalk

Thanks for all the help guys and so quickly! I’m quite embarrassed. I had it backwards how the button works. I was thinking when the button auto button red in upper right corner meant auto was turned off. I completely blanked out on that. My auto dimming mirror has always been a white icon and I’m guessing that was never on either lol. I really haven’t driven the truck all that much since getting it, so I never really paid enough attention.

Joe Gomez said:

Hi I’ve added the ATC with harness from M2. My question is does the heat only blow from the defroster and feet when using Auto? And does anyone else seem to feel when using auto in cold weather once the truck reaches the desired temp or slightly above it starts blowing cold air from the upper vents.

Click to expand...

I was just noticing this same thing this morning. I don't get any air from the dash vents when heating, even if I select that setting from the controls. Also, it was 7 degrees this morning and the defroster was putting out air that was barely warm (truck was warmed up). Temp was set to HI and manually selected defrost. 30 minute drive to work and still had a couple of spots of ice that I hadn't scraped off on the upper windshield.

The cool air temps when on HI is what has me most concerned. Is there a way to fix this?

ngiovas said:

I was just noticing this same thing this morning. I don't get any air from the dash vents when heating, even if I select that setting from the controls. Also, it was 7 degrees this morning and the defroster was putting out air that was barely warm (truck was warmed up). Temp was set to HI and manually selected defrost. 30 minute drive to work and still had a couple of spots of ice that I hadn't scraped off on the upper windshield.

The cool air temps when on HI is what has me most concerned. Is there a way to fix this?

Click to expand...

My truck definitely starts to blow colder air from dash vents once it reaches the desired temperature. That being said my truck defrosts the window and directs air to the floor only or floor and dash or just defrost depending on the conditions. I don't know if it's just me over thinking it but it seems to me ever since I installed the umility sensor even though the system technically works correctly it doesn't seem to work as well. I don't remember if blowing cold air from the dash prior to installing the humidity sensor when it was basically in the heat mode on auto.

Sent from my SM-G960U using Tapatalk

Ricks Ram said:

My truck definitely starts to blow colder air from dash vents once it reaches the desired temperature. That being said my truck defrosts the window and directs air to the floor only or floor and dash or just defrost depending on the conditions. I don't know if it's just me over thinking it but it seems to me ever since I installed the umility sensor even though the system technically works correctly it doesn't seem to work as well. I don't remember if blowing cold air from the dash prior to installing the humidity sensor when it was basically in the heat mode on auto.

Sent from my SM-G960U using Tapatalk

Click to expand...

I only have the temp sensor, no humidity sensor, so I don't think that is the issue. I do think it is related to the ATC modification. I wonder if there is a way in AlphaOBD to check the temp reading from the sensor to see what it shows.

When in Auto (got that figured out now lol) I noticed my truck doesn't defrost the windshield that well when starting it up or even after being on a bit on way to work. I manually push the defrost button on the right side by the temp button. The windshield then defrosts much better. When driving for a bit, if my windshield gets cloudy and wet in auto mode, I put it in defrost again and clears up. Once the truck "interior" is decently warm though, auto mode seems to work okay enough. -29*F for us in MN today. Not as cold as Canada gets usually, but cold enough lol.

One thing I noticed that's nice. Is if in auto mode, I hit the defrost hard button and run it for 10 minutes or so. I can hit the defrost button again and the truck defaults to auto mode without having to go back in to the software screen.

load97 said:

When in Auto (got that figured out now lol) I noticed my truck doesn't defrost the windshield that well when starting it up or even after being on a bit on way to work. I manually push the defrost button on the right side by the temp button. The windshield then defrosts much better. When driving for a bit, if my windshield gets cloudy and wet in auto mode, I put it in defrost again and clears up. Once the truck "interior" is decently warm though, auto mode seems to work okay enough. -29*F for us in MN today. Not as cold as Canada gets usually, but cold enough lol.

One thing I noticed that's nice. Is if in auto mode, I hit the defrost hard button and run it for 10 minutes or so. I can hit the defrost button again and the truck defaults to auto mode without having to go back in to the software screen.

Click to expand...

I agree. The ATC deffinently doesn't work as well as the factory dual zone ATC trucks. I mostly use it when I remote start the truck so I don't have to guess what to leave it set at. I usually switch it to manual when I am driving it the winter. In the summer I use it alot more and just keep it set at 72 to 74 degrees.

Sent from my SM-G960U using Tapatalk

ngiovas said:

I was just noticing this same thing this morning. I don't get any air from the dash vents when heating, even if I select that setting from the controls. Also, it was 7 degrees this morning and the defroster was putting out air that was barely warm (truck was warmed up). Temp was set to HI and manually selected defrost. 30 minute drive to work and still had a couple of spots of ice that I hadn't scraped off on the upper windshield.

The cool air temps when on HI is what has me most concerned. Is there a way to fix this?

Click to expand...

OK, I may have resolved my ATC issues. After a conversation with Mike (MPGrimm2), I decided to take the HVAC settings back to stock and reprogram everything using AlphaOBD. I had originally used my AEG which occasionally had unwanted side effects.

First, I have a 2015 RAM 2500. I originally added ATC early after it was determined it could be done. Because I have the 2500, I never added the humidity sensor. I don't drive my truck every day and less in the winter, so wasn't too concerned, but finally decided to try to correct the issues.

symptoms: Air coming from vents was barely warm, no air from front center vents even when manually selecting them.

Steps I took to correct the issue:

1. Returned HVAC to stock MTC settings using AlphaOBD
2. Disconnected battery to reset radio (note: I have a 2018 Panasonic radio, so I couldn't reset the radio through the tech menu).
3. It took one or two ignition cycles after changing to MTC and disconnecting the battery before the radio reflected the change.
4. Programmed module to dual zone ATC.
5. Disconnected battery to reset the radio, cycled ignition 2 times.
6. Tested air with dual zone settings and confirmed center front vents were working correctly.
7. Programmed single zone ATC.
8. Disconnected battery to reset the radio, cycled ignition 2 times.
9. Single zone ATC was back, but now it seemed to be working correctly (air from vents, hot air when on HI).

I recommend anyone having issues try to reset everything and try again. Check to make sure the changes took between each step. I don't know if AEG corrupted my settings, or if there was another issue, but everything is better now.

With that said, does anyone know what the air temp should be coming out of the vents? While it is much warmer, it still isn't real hot. It may be fine, but just want to check.

Nick

ngiovas said:

OK, I may have resolved my ATC issues. After a conversation with Mike (MPGrimm2), I decided to take the HVAC settings back to stock and reprogram everything using AlphaOBD. I had originally used my AEG which occasionally had unwanted side effects.

First, I have a 2015 RAM 2500. I originally added ATC early after it was determined it could be done. Because I have the 2500, I never added the humidity sensor. I don't drive my truck every day and less in the winter, so wasn't too concerned, but finally decided to try to correct the issues.

symptoms: Air coming from vents was barely warm, no air from front center vents even when manually selecting them.

Steps I took to correct the issue:

1. Returned HVAC to stock MTC settings using AlphaOBD
2. Disconnected battery to reset radio (note: I have a 2018 Panasonic radio, so I couldn't reset the radio through the tech menu).
3. It took one or two ignition cycles after changing to MTC and disconnecting the battery before the radio reflected the change.
4. Programmed module to dual zone ATC.
5. Disconnected battery to reset the radio, cycled ignition 2 times.
6. Tested air with dual zone settings and confirmed center front vents were working correctly.
7. Programmed single zone ATC.
8. Disconnected battery to reset the radio, cycled ignition 2 times.
9. Single zone ATC was back, but now it seemed to be working correctly (air from vents, hot air when on HI).

I recommend anyone having issues try to reset everything and try again. Check to make sure the changes took between each step. I don't know if AEG corrupted my settings, or if there was another issue, but everything is better now.

With that said, does anyone know what the air temp should be coming out of the vents? While it is much warmer, it still isn't real hot. It may be fine, but just want to check.

Nick

Click to expand...

You are definitely correct about the codes not setting all the way in some cases. It's important to make sure the changes are in effect when you go from the dual l zone ATC to the single zone ATC. I think that is the issue some people may be having when they do the conversion. As far as the air temp goes I haven't actually tested mine with a thermometer in my 2014 1500 but it deffinently gets very warm on Hi to the point of being uncomfortable. If you use it for a while and still feel its not warm enough you may want to convert it back to MTC and see if it makes a difference. I would also check for DTC codes in your HVAC system and if there are any write them down and then erase them and see if they come back.

Sent from my SM-G960U using Tapatalk

Thanks Rick. Hopefully I will have a chance to drive around a bit tomorrow and see how it does. It is definitely much warmer than it was the other day. I tested the temps in another car tonight and it was over 100 degrees F on the warmest setting. I will try to get some temps in the truck tomorrow.

Quick update - I went out and tested the truck today to take some temperature measurements.

When I initially started the truck and let it warm up a bit, I went to switch it from Auto to forward/center vents. After hitting the icon on the screen, it lit up indicating the change and I could hear something moving, but no air was blowing through the center vents. I was worried I was back to square one. I cycled through several settings, but couldn't get the air to blow through those vents. eventually I switched the temp from HI to a lower temp and suddenly the center vents started working again. From that point on, any combination of changes and the center vents always worked when they were supposed to. Fingers crossed that this issue is resolved.

Second thing I did was take some temperature readings using a laser thermometer. Last night while driving around in my sedan, I took a reading from the center vents (engine fully heated) with the temp on the highest setting and fan on high. The temperature was 118 degrees F. Today, did the same test in my truck after fully warming it up and got a temperature reading of 123 degrees F. That is officially hot in my book. I put the truck on auto and it appeared to be working great. Once the cab reached the right temp (had it set at 70) I could hear a baffle door moving and the air speed dropped and the air dropped to a warm but cooler temperature.

I would say that my issues are resolved. I would recommend to others having issues with cool but no hot air and no center vents to reflash the BCM back to manual and reprogram the HVAC system, checking after each step to ensure it is working.

Nick

Ricks Ram said:

I agree. The ATC deffinently doesn't work as well as the factory dual zone ATC trucks. I mostly use it when I remote start the truck so I don't have to guess what to leave it set at. I usually switch it to manual when I am driving it the winter. In the summer I use it alot more and just keep it set at 72 to 74 degrees.

Sent from my SM-G960U using Tapatalk

Click to expand...

Now that we have went from -35F to +25F, & multiple days of snow lol Iv'e had a chance to compare the truck to our 2019 Jeep Cherokee Trailhawk. Our Cherokee has factory dual zone auto temp control. I'd say our Cherokee isn't really any better at selecting front defrost or a blend of defrost and floor. My brother picked my wife and I up at the airport Monday morning & while driving home the Cherokee was in auto and the windshield and side windows got fogged up. So I put the controls on front defrost for a bit until the windows were better, than back to auto & it did fine until we got home 45 mins later. My wife drives the Cherokee mainly and says she has to periodically put it in front defrost and back to auto, which I didn't know.

So if anything, FCA maybe needs to tweak their (multiple vehicles) ratio of defrost and floor better/longer. Probably add a (better) sensor to detect frost/moisture buildup on the windshield even.

Thanks for the update that's good to know. I actually had my truck in a snowstorm for 3 days this weekend and left it on auto a lot of the time and it seemed to do pretty well but I did end up switching it to front defrost to try to keep the windshield wipers from freezing to the window.

Sent from my SM-G960U using Tapatalk

Hi guys,

First, great thanks to M2 mods to figured out all this stuff... I have some experience by doing this king of mods. I previously added the factory backup camera on my own research.

After reviewing the entire thread, I cannot find what I need...

It is simple, I currently have a ram 1500 2015 outdoorsman with 8.4 MTC climate and I want to switch to single zone ATC.

1. I need the temperature sensor
2. I need the humidity sensor with cover .
3. I need to build my own wire with 4 cables to connect the temperatur sensor to the HVAC module as really well describe in the first page of this thread with the wire schematic and parts needed.
4. I need to build my own wire to connect the Humidity sensor to the HVAC module....... This is what I'm searching for!!!! Do you have the same info than #3 above with schematic and part number needed for connector and pins to be able to conenct the humidity sensor?

Great thanks

Edit