Blend doors do whatever they want

[Myramisterrible]

14 6.7 longhorn. I've replaced all my blend doors,and hvac module.had it all calibrated. It worked that day. The next day I put it on defrost and it wouldn't go back to floor or vent.the next day it started on floor and wouldn't go to defrost. My drivers heat will go to cold one day but not the ne xt day. Today it went back and forth for 10 minutes then stuck on cold. Passenger side stuck in heat yesterday, works today.
I can't duplicate any results. Any ideas?

 

[Wiredawg]

Any codes? Since the truck is almost a computer, I would remove battery cables for 15min and do a reset to see what happens. More or less a system reboot.

Let us know if it works.

Cheers, Ron

 

[Myramisterrible]

Any codes? Since the truck is almost a computer, I would remove battery cables for 15min and do a reset to see what happens. More or less a system reboot.

Let us know if it works.

Cheers, Ron

 

[Myramisterrible]

Hi ron. I've taken the negative off,put back on, some actuators work but after a bit they are back to doing what what they want.
I don't have a scan tool,so I take it down to a local shop and have them do a actuator test (125 bucks).its always some thing different that fails the test.
Do you know if alphaobd will calibrate the actuators?
Not just test them but actually calibrate them.

 

[Wiredawg]

I just noticed your TDR name... interesting...

I have Alpha OBD, but haven't actually connected to my Ram... I used it on my Jeep. I googled and found where others had determined Alpha won't do it.

Found this:

I replaced my evaporator core last week because the old one was busted. Put everything back together, and then earlier this week, went and had the A/C system recharged. Well now that is all back together, when I turned the temperature control to "HI" is blows cold air, and hot on "LO". I called a dealership and they said the blend door actuator needs to be recalibrated. He said I could pull the positive and negative wires off the battery, hold them together for 10 seconds, and then reinstall them, and that MIGHT fix it. If not, I would need to take it to the dealership and hook it up to the scanner to have it recalibrated. My question is, does anyone know of a trick to recalibrate the system without taking it to the dealership. They want to charge $125 just to hook it up, which I don't want to pay unless I absolutely have to.

Another post mentioned Alpha can't recal the HVAC controller to the blend doors.​

My FCA SM references using FCA scan tool to do the recal. You might want to try removing all the battery cables and touching the neg and pos together. I've used 20 seconds for other resets on other trucks. Anyhoo, if all this fail, might need to go visit your friendly neighborhood Ram dealer for the recal.

Let us know what happens.

Cheers, Ron

 

[Myramisterrible]

Hi ron,
I have done the battery reset by touchinf cable together. The blend doors work correctly for about 5 minutes. Then goes back to not working corrctly.
So, i know its not the blend doors or the blend door actuators.
Sooooo??. Im kinda thinking a bad body control module.
The evic goes black when it warms up, and some times it flashes from bright to dim.
Every now and then i shut the door and the horn honks 3 times. One time i shut the door and the horn honked 3 times and locked the doors with the f.o.b. inside the truck!
Every now and then the radio and heater are not where i left them when i start the truck.

My tdr name comes from...... 27 warranty issues and another 7 that ive paid for. Its ben to 6 different dealerships. My local dealership is 30 miles away, next closest is 100 miles. The local dealership is usually 2 weeks to get it in. So sometimes i drive the 100 miles. And that doesn't count the recalls.
I wanted to buy a challenger for a road vehical. I drove one and loved it, the price was ok. I thought it over for 1/2 an hour....... drove down the block and bought an f150. I couldnt by another fca product!

 

[Wiredawg]

Hi ron,
I have done the battery reset by touchinf cable together. The blend doors work correctly for about 5 minutes. Then goes back to not working corrctly.
So, i know its not the blend doors or the blend door actuators.
Sooooo??. Im kinda thinking a bad body control module.
The evic goes black when it warms up, and some times it flashes from bright to dim.
Every now and then i shut the door and the horn honks 3 times. One time i shut the door and the horn honked 3 times and locked the doors with the f.o.b. inside the truck!
Every now and then the radio and heater are not where i left them when i start the truck.

My tdr name comes from...... 27 warranty issues and another 7 that ive paid for. Its ben to 6 different dealerships. My local dealership is 30 miles away, next closest is 100 miles. The local dealership is usually 2 weeks to get it in. So sometimes i drive the 100 miles. And that doesn't count the recalls.
I wanted to buy a challenger for a road vehical. I drove one and loved it, the price was ok. I thought it over for 1/2 an hour....... drove down the block and bought an f150. I couldnt by another fca product!

The fact that it worked a bit is reassuring. Did you check all connections and grounds associated with the BCM? You'd hate to buy a new BCM and STILL have the problemo. The BCM is under the dash to the left o believe.

Too bad you're not close to San Antonio. Some Shiner Bochs and BBQ I make for cheap help.

I'll look at my FCA SVC manual to see connectors and grounds. I'm very suspicious of them.

Cheers, Ron

 

[Wiredawg]

M.R.I.T.,
From my 2017 FCA Manual, the BCM has NOTHING to do with the HVAC, its the HVAC Control Module:

08 - Electrical / 8E - Electronic Control Modules / MODULE, HVAC / Operation
OPERATION
The Heating, Ventilation, and Air Conditioning (HVAC) Module utilizes integrated circuitry and information carried over the Controller Area Network (CAN) data bus to monitor many sensors and switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the HVAC module allows it to control electronic functions and features of the heating and A/C system.

Some of the inputs received by the HVAC module over the CAN bus are as follows:

• A/C Request
• Ambient Air Temperature
• Electric Back Light (EBL) Request
• Electrical System Voltage
• Engine Coolant Temperature
• Engine Speed
• Humidity, Windshield Glass Temperature and Dewpoint (ATC only)
• Refrigerant Pressure
• Vehicle Identification Number
• Vehicle Odometer

Some of the messages broadcasted by the HVAC module on the CAN bus are as follows:
​

• A/C Clutch Engage
• Auto Headlamp Signal
• EBL Status

The HVAC module receives the following information over hardwired circuits:

• Auto Headlamp Signal
• Evaporator Temperature
• Interior Air Temperature
• Left and Right Sun Load

The HVAC module monitors and controls the following over hardwired circuits:
​

• Driver and Passenger Blend Door Positions
• Blower Motor Speed
• Mode Door Position
• Recirculation Door Position

The HVAC module is diagnosed using a scan tool. Prior to replacing an HVAC module, run the calibration procedure to verify that the concern is not an air door calibration issue. (Refer to 28 - DTC-Based Diagnostics/HVAC - Standard Procedure) .



The HVAC module cannot be adjusted or repaired and must be replaced if inoperative or damaged.
​

Here is the wiring diagram:

There are a gazillion (20 to 30 pages) ) of trouble shooting with the Scan Tool. At this point, and your probably the last one who wants to hear this, but this was probably one of those things you need to take to the dealer to troubleshoot unless you just want to systematically replace everything.

BTW, checking grounds and connectors IS a checklist item.

Hope this helps. Ron

 

[TFucili]

When I replaced an actuator on my wife's old '06 Charger, I was able to dig up a long, drawn-out sequence of dashboard button pushing that would initiate a calibration for the HVAC. It worked like a charm.

 

[Wiredawg]

Tho\is could be what Tom was referring to for HVAC reset/RECAL:

https://ricksfreeautorepairadvice.com/recalibrate-chrysler-ac-control-head/

Can't hurt to try.

Ron

 

[Myramisterrible]

THANK YOU!
Many thanks ron. Thank you for helping me. I thank you for your service! If i where in texas i would buy you lunch for helping me and dinner for your service.
The hvac module is new. I ordered the new one from mopar parts online. Then i took it to a local shop, told them what i did and still no success. The local shop says they can do everything a Chrysler dealer can.
The wiring diagram you posted is to small to read and when i click on it ,i get Amazon.
Could you email it? y2khall@gmail.com
I will double check all my connectors and grounds. I have a young man helping me and a couple weeks ago i cought him pulling on wires when he was taking apart a connector.

A lil red express truck! Thats cool!

 

[Wiredawg]

You're very welcome on all counts... I'll be happy to email it, but have to do it from my laptop. It doesn't get bigger when you clickit on the diagram? I'll still send it anyway.

I'll also go back to look at ground points to see if I can find a common one or two to target inspecting and cleaning.

Cheers, Ron

 

[Wiredawg]

I cruised the LRE today.... have to be careful going into traffic... got a little squirrely getting into heavy traffic.... I love old muscle... not as powerful as wifes 19 Ram 1500, but has more character. and much louder.

Cheers. Ron

 

[Wiredawg]

Friend,

I pulled up connectors on my FSM and as you might guess, there's too much info to pull up. It's almost to the point if a truck owner intends to perform pmore than oil and fuel filter changes, it's almost a must to purchase the wiring and service manuals from FCA. I've purchased them on every vehicle I've owned except my wifes 2019 Ram 1500, which has lifetime extended warranty. Dealer preforms all maintenance on it.

Anyhoo, just wanted to let you know what we used to call LIMFACs (limiting factors) to mission accomplishment or readiness.

Cheers, Ron

 

[HPSimpson]

I cruised the LRE today.... have to be careful going into traffic... got a little squirrely getting into heavy traffic.... I love old muscle... not as powerful as wifes 19 Ram 1500, but has more character. and much louder.

View attachment 125247

Cheers. Ron

Wow must be clear warm day in beautiful Texas took the Lil Red Express truck out for a great ride how neat is that, Ron!

 

[TFucili]

Wiredawg's afternoon drive...

 

[Myramisterrible]

i am restoring my grandpa's 74 f100 4x4 swb.

 

[Myramisterrible]

Ok, finally got my heater fixed! I took it to a local garage. Took em 2 weeks. Put new actuators in it. The passenger actuator quit working after a couple minutes. A new heater box because the passenger blend door was binding plus a new actuator. Worked for a bit and quit. Another new actuator and an hvac controller, and wiring harness. Didnt work. Hours of testing. Finally found a bad connection at the hvac controller. They bent the pins in the controller just a bit to help make contact.
I had them put a new heater core in it while they where in there.... so after a year of frustration 3000 bucks I have warm toes!