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

[MarkCl]

Well... I have the same issue going on now. Hot on the drivers side and adjustable on the passengers side. I've located the blend door actuator for the drivers side and it does move when changing between LO and HI temp settings but the temperature does not. I can hear a mild change in air "sound" when the motor moves but no change in temp. Really not looking forward to the idea of having the dealer rip apart my dash only to make it never go back the same.

Im going to dig through FORscan and see if there is a relearn option for the HVAC system or similar.


Edit: looks like a common problem with the actuator but mine will move to both end points and still not change temp.

That construction will never last. It's similar to the axial encoders in the jet computers I used to work on during the Vietnam conflict. The military spent around $800 on some of those and they had tracks made of gold, and they still would go bad. Guys would make cufflinks out of those that were trashed.

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[rrwhitman]

Hello,

When adjusting temperature from hot to cold I heard a clicking noise from the blend actuator that is on the passenger side next to the glove box and would not get hot air. I took the actuator out - the shaft moves in response to adjusting temperature. I can also move the blend door lever manually pretty easily and get hot or cold air. Do you think the acuator is bad or is it possible that the pin of the blend door lever just some how jumped out of the slot of the blue acuator bellcrank? Appreciate your thoughts.

Robert

 

[AzScorpion]

Hello,

When adjusting temperature from hot to cold I heard a clicking noise from the blend actuator that is on the passenger side next to the glove box and would not get hot air. I took the actuator out the shaft moves in response to adjusting temperature. I can also move the blend door lever manually pretty easily and get hot or cold air. Do you think the acuator is bad or is it possible that the pin of the blend door lever just some how jumped out of the slot of the blue acuator bellcrank? Appreciate your thoughts.

Robert

Most times the actuator arm breaks but what you can't see is the heater box is warped too. It sounds like your heater box is warped and the gear is about to break by the sound of the clicking noise. This happened to me on my '19 and I just manually moved the silver knob back and forth for heat/cooling.

 

[rrwhitman]

Thanks for the reply. When you say the gear is about to break, do you mean inside the actuator? The actuator is easy to replace - if I can replace it and get a few years (perhaps consciously not adjusting the temp a lot) I would be okay with that, versus completely tearing the truck apart to to replace the heater box.

 

[AzScorpion]

Thanks for the reply. When you say the gear is about to break, do you mean inside the actuator? The actuator is easy to replace - if I can replace it and get a few years (perhaps consciously not adjusting the temp a lot) I would be okay with that, versus completely tearing the truck apart to to replace the heater box.

Yes the gear is very easy to replace but the heater box could be warped. If it is warped (it most likely is) then it will unfortunately just happen again.

 

[rrwhitman]

Just like Blue Streak's photo in post 381, I can see where the pin on the white lever jumped out of the slot in the blue cam, preventing its normal travel. I know that the underlying issue is warping but I'm hoping an easier fix than replacing the whole box could be something that prevents the pin from jumping out of the slot. I believe the pins are jumping out of the cams (on both the passenger side of a manual A/C truck and the driver's side of dual zone models) because the white levers/pins are out of alignment due to warping. Still, I want to consider extending the pin, eliminating any play between the blue cam and the white lever/pin, etc... in hopes of keeping the pin from escaping the slot in the cam. Thoughts? Thanks!

 

[airline tech]

Hello,

When adjusting temperature from hot to cold I heard a clicking noise from the blend actuator that is on the passenger side next to the glove box and would not get hot air. I took the actuator out the shaft moves in response to adjusting temperature. I can also move the blend door lever manually pretty easily and get hot or cold air. Do you think the acuator is bad or is it possible that the pin of the blend door lever just some how jumped out of the slot of the blue acuator bellcrank? Appreciate your thoughts.

Robert

With the actuator out and you (electrically) move it with the controls, if you wrap your finger around the shaft (create) a small amount of resistance - Will the actuator start popping?

I would pull it apart, clean it and inspect the gears - then lube it and reinstall if gears look good.
or
Just replace the actuator and see how it works.
Now this may cure the issue altogether or extend the normal operation for a while as it will depend on (IF) the internal door is binding - it will eventually take out the actuator again.
The popping noise is the plastic gears jumping (as its jumping) the gear teeth are being chewed off.

Another item to (Inspect) is the Arm that sticks out of the HVAC box is is straight, if that is bent the PIN will not ride in the bell crank the way it should and wants to pop out of the guide as it rotates around this is another area of the popping noise, as play and or binding of the (Internal) door causes the actuator and associated bell crank to bind up - the torque action of the actuator motor attempts to overcome this bind and continues to drive past the bind to move to the commanded position.
So, this creates the bending of the actuator lever as well as the gear jumping inside the actuator.

If the pin has been jumping out of the bell crank, you will see score marks on the bell crank on a close inspection.

 

[rrwhitman]

I did try to stop the movement of the actuator when it was commanded by the controls and I was unable to. Opening and examing the actuator's gears I do not see any damage at all. I do see scoring where the pin jumped out of the slot of the blue cam/bellcrank. I noticed the noise (sort of a slight thumping noise) when attempting to select cold air - from that point on I could not change the air temp. Cycling between hot and cold I could hear the actuator but get no change in air - I believe because the pin was not in its slot. This isn't something that has been degrading - it happened once and that was it. I'll put the actuator back in tomorrow and look carefully at the white lever and pin alignment, see if there is a way to improve it, and watch it all in action. Thanks again.

 

[rrwhitman]

I just plugged the actuator back in (to make sure it was fine after popping its cover) and cycling back and forth between hot and cold it moves fine. Trying to hold against the rotation of the blue bellcrank demonstrates that it is quite strong! I cannot imagine the air blend door or shaft binding tight enough to strip the gears of the actuator. I think the white lever pin jumps out of the blue cam slot (due to warping induced misalignment) and then real mayhem begins. Anyway, more tommorow!

 

[Blue Streak]

When mine failed I could see on the blue bellcrank where pin had rubbed it.

I did try to stop the movement of the actuator when it was commanded by the controls and I was unable to. Opening and examing the actuator's gears I do not see any damage at all. I do see scoring where the pin jumped out of the slot of the blue cam/bellcrank. I noticed the noise (sort of a slight thumping noise) when attempting to select cold air - from that point on I could not change the air temp. Cycling between hot and cold I could hear the actuator but get no change in air - I believe because the pin was not in its slot. This isn't something that has been degrading - it happened once and that was it. I'll put the actuator back in tomorrow and look carefully at the white lever and pin alignment, see if there is a way to improve it, and watch it all in action. Thanks again.

Keep us posted on your findings.

 

[airline tech]

This is all based on my opinion - for posted results on the doors move freely and what else could be happening here. It's clearly not binding.

Ok, since reviewing @quangdog video and others that state that the doors move freely, I can pretty much deduce the issue is not really the door binding but the shaft the doors ride on is (warping -bending- flexing) whatever term you want to use - thus (SHORTENING) the distance the (White) arm sticks out of the end of the box and makes it a wobbly effect as it guides into the (Yellow) Bell-Crank. (Moves - In & Out) when it moves (IN) it pops out of the Guide Track.

There is not much you can do about actual repair, as it is unknown if - the shaft is bent or is it (Axial) play allowing the movement.

Being that the (White-Arm) is removable, however no known (available) part separately for purchase, makes this expensive if that arm breaks or the pin breaks off.
The shaft also cannot be replaced unless you replace the whole box.

So being that you have a fairly accessible passenger side actuator, you MAY be able to find a solution to overcome the shaft being bent, worn etc.

Some off handed ideas:
1. Investigate the white arm (shaft) to see, if possible, to insert something (Rubber/Foam Etc) at the end of the shaft - That would keep it in a smooth rotation. Hard to explain but this would be to keep the (white arm) in a smooth rotation (not-wobbling) out of the bell crank and take out any axial movement that may be happening.

2. See if the (PIN) in the white arm will come out (without breakage) and if so, find a suitable replacement that is longer - but you would have to pay attention to how far the OEM sticks out and the clearance to the inner side of the Bell Crank - so it's not touching / rubbing.
So, this would allow the door shaft to continue as it is, but the pin will still be long enough that it will not pop out of the guide. (Example would be a Pop-Rivet shaft)

3. See if it is possible to (file) the end of the (Yellow) Bell-Crank without affecting how it mounts to the box, my thought is - shorten the distance between the Bell-Crank and the Yellow (Pin).
I think the mount points of the actuator may not allow this to be a solution. But it is just thought.

These are just some ideas that I have to avoid replacing the box, just have to be careful not to break anything, I believe the Bell-Crank comes with a new actuator or it can be purchased separately.
And these ideas are under the assumption that I am correct on my assessment on what is happening with that shaft, and with this on the passenger side vs the driver's it does allow for some possible band-aid fixes. Will they work -IDK but if you are looking at a box replacement it may be worth an attempt at the band-aid.

If you do not see any axial movement in the white arm, then closely inspect the (Yellow - Bell-Crank) for flatness or wear on the guide (worn off) on the edges that would allow the pin to pop out.

REf:

Checking Out Old Heater Blend Box 2019 Ford Ranger

and

White arm on blend box

 

[rrwhitman]

Great videos - thanks for those. We are thinking along the same lines. It doesn't seem likely that the shaft/doors are binding anywhere near enough to damage the actuators. I believe the pin of the white lever is jumping out of the slot of the (in my case) blue cam due to the white lever no longer being parallel to the blue cam because of warpage somewhere. Your suggestions number 2 and 3 - lengthening the pin or tighenting up the clearance between the white lever and blue cam - seem worth pursuing. I am thinking that a greased nylon washer between the blue cam and the body of the actuator would push it tighter against the white lever and pin. Or, slightly shaving the mounting bosses of the actuator would also move it closer and tighten the clearance. If the white lever is now slightly angled exiting the heater box, shaving the appropriate actuator mounting boss could slightly angle the acutator to match the white lever, like adjusting a three legged stool, and bring the two into better alignment. I don't think you could do any of this on the driver's side but it is all pretty accessible on the passenger side. Thanks for your input!

 

[rrwhitman]

Added two nylon washers between the blue cam and the body of the actuator which moved the cam out about 1/16 inch and tightened it up against the white lever/pin. Back together and working - will post if the pin jumps out of the slot in the future. At least I have heat - 20's in the a.m.

 

[Blue Streak]

Added two nylon washers between the blue cam and the body of the actuator which moved the cam out about 1/16 inch and tightened it up against the white lever/pin. Back together and working - will post if the pin jumps out of the slot in the future. At least I have heat - 20's in the a.m.

That is what I was thinking of doing shimming out the cam. I was going to make sure there was enough depth in the slot the pin rides in. Let us know how it works out.

 

[airline tech]

Added two nylon washers between the blue cam and the body of the actuator which moved the cam out about 1/16 inch and tightened it up against the white lever/pin. Back together and working - will post if the pin jumps out of the slot in the future. At least I have heat - 20's in the a.m.

Cool, so the Bell-Crank has some play (in between) the Box & Actuator.
So, in the (OEM) set-up installed you could reach your fingers up and pull the Bell-Crank away from the box. (Play)

For other members benefit, what was the I/S diameter size of the nylon washers?
Congrats on the Band-Aid resolution - hopefully it will last

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