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

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Mpgrimm2

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Does the new v2 harness take care of both the cabin temperature sensor and the humidity sensor with the one harness???
Yes but it's a 2 part harness...

1st part:
ATC Sensor harness that plugs into the HVAC module same as before for all 13+ trucks

2nd part:
Humidity Sensor harness that plugs into the mirror header harness behind the pass. air vent & connects to the first harness . Only req'd for 14-18 1500's (not req'd for 13+ 2500/3500s)

M² Mods.
 

sawz

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(courtesy of Ricks_Ram)
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Wiring 68207371AD

I've looked through the thread and don't see it, does anyone have the plastic cover PN that goes over the humidity sensor?

Thanks,
Pete
 

Ricks Ram

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I've looked through the thread and don't see it, does anyone have the plastic cover PN that goes over the humidity sensor?

Thanks,
Pete
I ordered the plastic cover with my humidity sensor and there's really no place to mount it because the windshield does not have the correct mounting brackets. I just ended up sliding humidity sensor in between my headliner and the window and it's really not noticeable at all.

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sawz

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I ordered the plastic cover with my humidity sensor and there's really no place to mount it because the windshield does not have the correct mounting brackets. I just ended up sliding humidity sensor in between my headliner and the window and it's really not noticeable at all.

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yes, that was my understanding of the cover, that the mount for it is actually considered part of the window and not orderable separately for some reason. I was going to see if I can figure out a way to utilize it and give a "stock" look.
 

Ghost_RAM

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I haven't done it yet either but was going to try some 3M double sided or butyl being careful where applied of course.
 

crash68

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Does the factory mounted humidity sensor get pushed against the glass? or is there a gap? I ask as it looks like there might be temperature sensor on the glass side. If that is the situation, it is probably a dew point sensor.
 

Ricks Ram

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Does the factory mounted humidity sensor get pushed against the glass? or is there a gap? I ask as it looks like there might be temperature sensor on the glass side. If that is the situation, it is probably a dew point sensor.
You're exactly right it has a dew point sensor and that's why I put it between the headliner and the window because the headliner holds it off the window by a very slight amount just enough to give it to gap it needs but yet not too far away.

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sdwalter

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So I spent the last few hours reading through this thread. I upgraded from the RA2 to the RA4 radio through infotainment. I installed the 7 speed fan controller module on the passenger side of the dash with the upgrade and have the dual temp auto controls with the bezel upgrade that came with the kit. If I wanted to switch from MTC to ATC, I would need the following:

1. Cabin Temp Sensor
2. Temp Sensor Wiring Harness from M2
3. Humidity Sensor
4. Humidity Sensor Wiring Harness from M2
5. AlfaOBD or OBDGenie

Does that sound right?

Also, upgading to dual ATC is crazy because you have to replace the entire plenum system (all new dash)
 

sawz

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sorry, wrong thread
 

sawz

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I took some pictures while installing the humidity sensor harness.

First I removed the passenger side air vent, simply use a plastic tool and CAREFULLY remove the vent.
20181007_103635.jpg

Next, locate the two plugs, one for the temp sensor harness, the other for the mirror humidity sensor harness.

20181007_103914.jpg 20181007_103921.jpg

There is a red locking tab on the humidity sensor harness that you need to unlock to unplug the connector

20181007_104047.jpg

Now install the two harness in-between the original harness and plug.

20181007_103644.jpg
 

sawz

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Next connect the Temp harness and humidity sensor harness small white plug together.

20181007_104505.jpg

Take the passenger window grab handle trim piece off by using the plastic tool to open the two covers over the bolts. Remove the bolts with a 10mm socket.

20181007_105537.jpg 20181007_105649.jpg
 

sawz

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Now to run the harness up to the mirror. I followed the original harness routing. There are some clips that I used to secure the wiring in the original harness.

20181007_105723.jpg 20181007_105810.jpg 20181007_105904.jpg

Tuck the wiring along the front edge of the headliner and route to the middle of the truck over the mirror.

20181007_111047.jpg

The mirror is easy to remove from the windshield, simply twist and it will come off. To put back on put it back up there and twist the other way while putting some pressure on it. The "nut" that is attached to the window is not completely symmetrical, three of the edges are closer together than the others. The trick to put the mirror over the smaller part then twist to lock it in place.

I decided to double sticky tape the sensor to the inside of the mirror cover.

20181007_111930.jpg

Simply reinstall the covers you removed and you are done!
 

Ricks Ram

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Nice write up! I didn't think to take pictures when I did mine. It's really not as difficult as people might think. I pretty much did it the same way you did but I mounted the sensor in between the headliner and windshield.

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Jkieffer

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Ok. I am just trying to clarify a couple things before I start to take apart things. I ordered the humidity harness from benny early on but have not attempted to put it in as I was also attempting to get a smart beam / auto dim mirror at the same time. Do I need a actual jumper wire for power with the harness provided by benny?

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Ricks Ram

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Ok. I am just trying to clarify a couple things before I start to take apart things. I ordered the humidity harness from benny early on but have not attempted to put it in as I was also attempting to get a smart beam / auto dim mirror at the same time. Do I need a actual jumper wire for power with the harness provided by benny?

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Yes. You will need to run a jumper wire from the #2 pin on the HVAC module to the mirror harness to bring ignition on power to the sensor. You can get your harness and everything installed and then possibly order a jumper wire from M2Mods and put that in after the fact but it wont-work until you add the wire.

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