SSM 49264 - Climate Control Temperature Will Not Adjust With Clicking/Snapping Noise From The Dash

[airline tech]

What a wild ride. Just read the whole thread. Thanks for everyone's input.

I think my symptoms are slightly different than others?

Outermost driver side vent blows ice cold when set to Lo.

Passenger only blows ~ambient when set to low.

Both blow full hot when temp set high. Both actuators move freely, no clicking.

I removed the passenger side actuator and cycled the blend door by hand. Seems to move freely. Passenger side still blows ambient with the blend door held firmly in the cold position by hand.

Not sure where to go from here...

If moving the passenger door by hand and still getting ambient air, the only thing that would cause it would be that the door is not fully closed and blocking the heater core airflow.
So a false feel of the stop as you manually move it or piece of the door broken off or a piece of the foam seal or debris is stopping the door from fully closing.
The actuator is not popping or clicking as it has recalibrated itself to learn the new (LO) position as it’s stop - if you have debris stopping the door from fully closing.

This is where an actual visual video on operation will help, as I can only go by pics and description. This is what quangdog can possibly supply after he gets his back in working condition using his old broken unit as a reference.

I am curious if one could get access to the floor duct outlets on the HVAC box and use a boroscope camera to actually see the internal movement of the door

Sponsored

 

[mistertierney]

That's a great idea with the boroscope. I will try that later today. When moving the passenger actuator by hand, it felt like a nice firm close. I could almost swing the door closed to the cold side with momentum and could hear a firm slam, but still only ambient air.

I was expecting to feel some stiffness or binding, which I did not.

Thanks for the input.

 

[airline tech]

That's a great idea with the boroscope. I will try that later today. When moving the passenger actuator by hand, it felt like a nice firm close. I could almost swing the door closed to the cold side with momentum and could hear a firm slam, but still only ambient air.

I was expecting to feel some stiffness or binding, which I did not.

Thanks for the input.

Not sure if enough room to snake scope into the heater core area from the passenger side but the door will be right above it.

 

[Blue Streak]

Airline Tech photo of scaring from pin. All gears seem to be good.

 

[Bsthroop]

Ordered my heater case today so hope to complete the repair in the next month.

 

[MarkR]

Airline Tech photo of scaring from pin. All gears seem to be good.

Airline Tech photo of scaring from pin. All gears seem to be good.

Took some pictures of my defective box and the drivers side pin seems tilted. Almost like the rod was too short and caused the center of the pin to be pulled in towards the box. Doesn’t look fixable without replacement. Every time I tried reseating the actuator it never felt flush and would always jump off the pin

 

[airline tech]

Took some pictures of my defective box and the drivers side pin seems tilted. Almost like the rod was too short and caused the center of the pin to be pulled in towards the box. Doesn’t look fixable without replacement. Every time I tried reseating the actuator it never felt flush and would always jump off the pin

Looks like the door was binding internally and the actuator was trying to push past the bind, and it bent the lever, now the pin will not ride in the guide correctly and pops out.

 

[MarkR]

Looks like the door was binding internally and the actuator was trying to push past the bind, and it bent the lever, now the pin will not ride in the guide correctly and pops out.

I’ll double check but it doesn’t feel bound up. I’ll remove the other actuators and compare

 

[mistertierney]

Strong work and thanks for posting pics gentlemen.

Here's what i found on my 2020 today:

Blend doors are working correctly, for now.

Topped off refrigerant with R1234yf. Low side pressure was at 12psi, brought it up to ~35psi @ 25C ambient.

AC blew cold right away. Found a significant leak with UV light at the condenser to compressor hose fittings.

Factory refrigerant has dye in it.

 

[airline tech]

I’ll double check but it doesn’t feel bound up. I’ll remove the other actuators and compare

Or it could be actuator feedback, internally got lost and continued to try to drive the door and bent the lever.
Basically, we know that this is an issue, but we have not found specifics on the cause.
I agree that the lever appears bent, and it’s the cause of it coming off of the bell crank.

It just needs to be investigated as to what caused the lever to bend in the first place.

As it sits at room temperature, you are only missing (2) factors and that is 190 degrees of heat on those doors.
Heat Expands.

And power for the actuator:
Missing the actuator drive, at some point in time did it not stop electrically and continued to try to force the door to close / open.
And bend the lever in the process.

I am curious if you pulled it apart would it show evidence internally like the lever does.

 

[MarkR]

Or it could be actuator feedback, internally got lost and continued to try to drive the door and bent the lever.
Basically, we know that this is an issue, but we have not found specifics on the cause.
I agree that the lever appears bent, and it’s the cause of it coming off of the bell crank.

It just needs to be investigated as to what caused the lever to bend in the first place.

As it sits at room temperature, you are only missing (2) factors and that is 190 degrees of heat on those doors.
Heat Expands.

And power for the actuator:
Missing the actuator drive, at some point in time did it not stop electrically and continued to try to force the door to close / open.
And bend the lever in the process.

I am curious if you pulled it apart would it show evidence internally like the lever does.

Didn’t pull it apart yet but the drivers side is a lot harder to turn. Tried to upload a video comparison but the file’s too big. Guess I wasted my time taking videos

 

[quangdog]

My new heater box arrived yesterday. I'm tied up this weekend with other projects, but am planning to do this replacement next weekend. I took a bunch of photos of the new box last night. It arrived with actuators installed, and all the doors at pre-set positions. I cannot manually change the position of any of the doors without removing actuators, and I'd prefer not to do that on the new one.

Once I have my old one out, I'll be glad to disassemble it however much is needed to get whatever photo and video reference that would still be helpful.

Here are a bunch of detailed photos of the new one:

 

[Blue Streak]

Airline Tech & all others interested. I had to use my truck today to pickup some supplies. I can confirm by make shift cable is functional as I was able to adjust the temp. I took a picture of the drivers side best I could & it appears there is no actuator on the drivers side with manual a/c.

 

[MarkR]

My new heater box arrived yesterday. I'm tied up this weekend with other projects, but am planning to do this replacement next weekend. I took a bunch of photos of the new box last night. It arrived with actuators installed, and all the doors at pre-set positions. I cannot manually change the position of any of the doors without removing actuators, and I'd prefer not to do that on the new one.

Once I have my old one out, I'll be glad to disassemble it however much is needed to get whatever photo and video reference that would still be helpful.

Here are a bunch of detailed photos of the new one:

Yep you’re good to go. Be nice if you could find the two screws that face the firewall and exchange them for screws that take a Phillips or socket. Those two were a pain. A lot of hand cramping and cussing. A ratchet would’ve be really nice.

 

[Bsthroop]

Yep you’re good to go. Be nice if you could find the two screws that face the firewall and exchange them for screws that take a Phillips or socket. Those two were a pain. A lot of hand cramping and cussing. A ratchet would’ve be really nice.

What type of head do those have?

Sponsored