Odd AC Issues 2016 2500 Cummins

[gnut]

So i didn't know where to post this so I'm trying general. For over a year my AC was crazy. It would randomly stop working, rebooting the truck or turning it off and on seemed to work... until it didn't. Took it to shop 1 they said trash in the compressor system AND hvac control module bad. I got another hvac control module from a junkyard albeit a different part nunber from the original (original ends in AA this one ends in AB). Baam, AC... but with trash in the line I know it's a matter of time until compressor goes so I get it replaced at shop 2 (shop 1 pissed me off). Their diag was compressor AND under the dash actuators. They said it was stuck on AC recirculating. So no way the hvac control module, all actuators and compressor happened at the same time. They said they can manually activate the actuators under the dash but i asked if that would actually be the hvac control module. Could my new control module be wrong since its a diff part number and that is causing the under dash actuators?
$1700 for the compressor and related, shop1 wanted $2000 for hvac module (part was $1800 and labor was $200 so it had to be the knobs thing that i replaced with junkyard part). Shop2 wants dang near $2000 for replacement of under dash actuators (mostly labor as dash has to come out). Shop1 is a higher caliber shop normally than shop2.

Any AC guys on here willing to lend me advice? I am an IT professional so I am willing to trade computer advice now or in the future to anyone who can help me.

 

[aszumilo]

AB is just an updated version of the part, as long as the numbers are the same you should be fine on that part.

 

[gnut]

AB is just an updated version of the part, as long as the numbers are the same you should be fine on that part.

I thought as much. How can I verify the in dash actuator are bad? It's odd one shop said control and another said actuator. Shop2 said there were codes but those codes weren't there prior to the new hvac module i installed.

I guess I need to go to the stealership?

I'm going to pull the hvac module and verify part number this weekend but I'm pretty sure you are right because it looks identical.

 

[crash68]

@gnut as mentioned above if the part number is the same and it just the last letter that changes it's an updated part that should be backwards compatible.
If your looking to do your own work it maybe worth to get AlfaOBD along with a OBDLink MX+ OBD reader. AlfaOBD can not only modify body parameters but also perform diagnostics, read live operating data along with reading/resetting vehicle error codes(more than typical OBD readers).
There is options in AlfaOBD for testing the HVAC system actuators.

 

[aszumilo]

You could try to recalibrate the blend doors actuators.

I think this is the procedure for your truck

Step 1: Turn your fan to the lowest possible setting.
Step 2: Hold down the climate control/conditioning button for 10 seconds.
Step 3: Let go of the button, then press and hold it again until the lights on the button start flashing.

 

[jws123]

It sounds to me like you need to find a better place to take your truck and that they are guessing.

 

[gnut]

@gnut as mentioned above if the part number is the same and it just the last letter that changes it's an updated part that should be backwards compatible.
If your looking to do your own work it maybe worth to get AlfaOBD along with a OBDLink MX+ OBD reader. AlfaOBD can not only modify body parameters but also perform diagnostics, read live operating data along with reading/resetting vehicle error codes(more than typical OBD readers).
There is options in AlfaOBD for testing the HVAC system actuators.

I have alphaobd but I couldn't figure out where hvac diagnostics are. So if I tell it to close an actuator is it telling it directly or telling the hvac controller in the dash? That is my question, my guess is alpha would tell the hvac contoller (thing on the dash with the knobs) to do something and it would operate the actuators as opposed to operating them directly...so if an actuator doesn't do something it could be the actuator or controller?

See my logic?

 

[gnut]

It sounds to me like you need to find a better place to take your truck and that they are guessing.

The shop1 is the best in the area and the only place besides the dealer that can work on diesels...shop2 was recommended by a friend...i know shop1 has all the fancy diag equipment but shop2, i don't know.

Shop1 said contoller and 2 said actuator in dash so I'm wondering if indeed the controller would set the same flag. Their diag equipment says to open actuator wouldn't the computer tell the hvac module to open the actuator?

 

[gnut]

You could try to recalibrate the blend doors actuators.

I think this is the procedure for your truck

Step 1: Turn your fan to the lowest possible setting.
Step 2: Hold down the climate control/conditioning button for 10 seconds.
Step 3: Let go of the button, then press and hold it again until the lights on the button start flashing.

I'm going to try this. I'm told its stuck on cold so I'm hesitant to do anything as long as i have ac. I got that recall notice so maybe I'll ask the stealership to do the emissions recall and look at the AC while its there... but damnit I want to figure it out. As a computer guy i just don't know the logic of the hvac control and actuator

 

[gnut]

AB is just an updated version of the part, as long as the numbers are the same you should be fine on that part.

I'm going to pull it tonight and make sure. Do they also change the last numbers? Mine ends in 180AA and i found one online that is 190AA... would these be compatible?

 

[crash68]

I have alphaobd but I couldn't figure out where hvac diagnostics are.

I believe you connect to the Climate Control module then use code scan button at the bottom.

 

[gnut]

I believe you connect to the Climate Control module then use code scan button at the bottom.

I did that and there was so many options i was afraid of mucking something up. I'll look again

 

[chopperman1]

Take your original control module part number and put it in to pretty much any Mopar online parts suppliers website. It will tell you the replacement/updated part number. The numbers don't usually change, just the last 2 letters, ie 123456789AA, 123456789AB, AC etc

 

[chri5k]

I have alphaobd but I couldn't figure out where hvac diagnostics are. So if I tell it to close an actuator is it telling it directly or telling the hvac controller in the dash? That is my question, my guess is alpha would tell the hvac contoller (thing on the dash with the knobs) to do something and it would operate the actuators as opposed to operating them directly...so if an actuator doesn't do something it could be the actuator or controller?

See my logic?

The knobs on the dash, HVAC module and the door actuators are all on the CANbus. The knobs send a message to the module to make air come from the dash and floor. The module sends messages to the appropriate doors to open or close. All through messageAlfa tells the module to move door 1 and the module signals door 1 to move.

 

[gnut]

Ok, so if the HVAC module is bad then slphaobd or another scan tool will not be able to open and close the actuator? I really hope this is what you are saying.

(I'm impressed by your knowledge. Mechanic?)

 

[gnut]

AB is just an updated version of the part, as long as the numbers are the same you should be fine on that part.

Here are the part numbers, so i assumed the yard sold me one from a 2500...they said they did and its a larger professional operation not just some small rinky dink. Do i need to seek out another one?

P68236775AB - junkyard version
P68268189AA - original

I found one on fleabay that is P68268190AA...

 

[aszumilo]

Not sure if the fleabay one will work.

Checked one of the Mopar parts sellers and this is what they have, based on your original part #
Looks like the junkyard one you got would work

• Brand:
  
  
• SKU: 68268189AA
• Other Names: Control
• Condition: New
• Replaces: 68105021AC, 68105021AD, 68105021AE, 68105021AF, 68226600AA, 68226600AB, 68236775AB
• Sold In Quantity: 1

2013-2018 Ram A/C And Heater Control 68268189AA | Mopar Online Parts

2013-2018 Ram Part # 68268189AA - A/C And Heater Control

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