[20grand]

I posted about this a couple months ago and today I looked a little more into it. I read in other threads that a faulty actuator can be the reason why I have cold air blowing under the dash while the heat is on. I took a picture of what I THINK is the actuator. Does this look right?

Also, I noticed where the cold air is coming from is way back towards the firewall. I can't really see a vent. I took a picture of the area where the cold air is coming from, back by that bolt that is on the firewall. I ran the codes but no codes for faulty actuator doors. Just the same ol brake wear sensors and tpms that I'm already aware of. Any thoughts??

 

[Ranger]

The first picture is 1 of 4 actuators. The second is the blower.

 

[20grand]

Do you think it's the actuator shown is giving me the problem? I unplugged it and didn't notice a thing different. It's blowing ICE COLD and I need all the heat I can get out of her this time of year.
It's odd that other posts show codes but mine does not.

 

[centaur]

Well if the actuator is stuck in the "cold air" position...unplugging it won't change anything. Did you try to "exercise" it with the controls to see if that one operates?

Sometimes the actuators get out of sync and you can save them by running the temp down to minimum for a few mins, then to max and then back down to your desired temp once you feel the temp stabilize on each side. Also try it with the climate control in dual mode, excercise both sides seperately and then equalize them and then go back to auto. And being you have issues, it's probably best to keep it in single mode too, shut the passenger side off.

I had to do this several times over a few driving cycles on my SLS when winter started, and it has finally re-calibrated itself and my heat works well now. I also disconnected the battery and touched the two terminals together for a few secs to do a reset on all the electrical modules. Worth a try.

If not, your best bet to get by for now, until you get another actuator, is to disconnect the arm to move the door manually to the closed position. That way, the worst thing you end up with is too much heat, which you can drop the fan speed or close vents off to help tolerate it, way better than no heat at all.. This is assuming you've found the correct faulty actuator. As Ranger said, there are four...

 

[20grand]

I tried going through the cycles quite a few times but that didn't help. I read in a few posts that different actuators control different vents. I wasn't sure if this actuator is the one making the car blow cold. If so, this would be an easy swap.

I would manually move the door but I don't see where to do that.

 

[centaur]

Probably need to unbolt it and pull it away to see the rod that goes to the air door, it's attatched to the arm on the actuator motor. Once removed, you should be able to move the rod freely to open and close the fresh air door manually. You may have to secure the rod in place to keep it closed while you source a new actuator.

Before doing this cycle through the temps and make sure this actuator is the dead one or is out of range. Some will still work, but the are stripped inside and just spin all the way around and miss the stops.

Then again, if you have no codes, someone here is likely to have a parts manual exploded diagram to show you and will know which one is failing. Beg Ranger or Sub, they usually have all that info. I'm just going on foggy memory here, last changed one many full moons ago.

 

[Ranger]

Do you think it's the actuator shown is giving me the problem?

You said "I have cold air blowing under the dash while the heat is on". Does that mean you have heat from other modes (dash vents and defrost) or no heat control at all.

 

[walliss34]

I got the same thing going on with my 99 STS, passenger side blows cold air,,i will try to exercise her again, but on my Deville I had to change the actuator, that 1 was easy though cause the arm was external and I unhooked it for a while leaving it closed and it just blew hot air then. Is the 2001 and 99 the same under da dash?

 

[Ranger]

Is the 2001 and 99 the same under da dash?

I don't believe so. The '99 was vacuum operated I believe and the 2000+ is electronic.

 

[20grand]

@Ranger I have heat coming from everywhere except for a vent I can't see towards the back by the firewall on the passenger side. There's even a smaller vent that's kicking hot air that's closer to the dash on the passenger side.

----------

@centaur. Thanks for the feedback. Worse comes to worse, I'll just manually move the door. It's just that the car gets half warm and it's not enough when it's 5 degrees out.

 

[Ranger]

Kind of sounds like half of the dual zone is not working properly.

 

[centaur]

I don't believe so. The '99 was vacuum operated I believe and the 2000+ is electronic.

My 97 STS had electronic actuators...I'm sure vacuum operated ones are only on manual climate control systems.

 

[Ranger]

:hmm: There is no manual climate control on Cadillacs. My '97 Deville was vacuum operated.

Curiosity got the best of me so I looked it up.
Here is a diagram of the '97 Seville HVAC control system complete with vacuum lines. (I believe there is one electrical actuator on top of the HVAC unit, above where the vacuum lines enter it (visible, but not numbered)).

This one shows the two vacuum actuators above the hose ends.

And here is a closer look at the two actuators (#3 & 4)

 

[centaur]

I meant manual controls and vacuum on any cars in general, was it the 80's when Caddies last had manual controls?

Okay, so I'm stumped Ranger. Due to getting cold air coming in on one side...I remember fixing the problem by changing what I thought was an electronic mode door actuator that was behind the glove box on my 97 Seville.

So, I guess my assumption that the whole system was electronic is incorrect. That and I should know better than to question a Ranger who comes armed with FSMs at the hip. Don't those get heavy after awhile? Lol!

 

[Ranger]

I meant manual controls and vacuum on any cars in general, was it the 80's when Caddies last had manual controls?

Actually my '71 Deville had Automatic Climate Control.

Okay, so I'm stumped Ranger. Due to getting cold air coming in on one side...I remember fixing the problem by changing what I thought was an electronic mode door actuator that was behind the glove box on my 97 Seville.

So, I guess my assumption that the whole system was electronic is incorrect.

Not entirely. The dual zone was electronic, but I believe, as the diagram showed, the rest was still vacuum.[/QUOTE]

That and I should know better than to question a Ranger who comes armed with FSMs at the hip. Don't those get heavy after awhile? Lol!

 

[MoistCabbage]

Off topic - Ranger, what colors way your '71? And when did you own it? Just curious.

 

[20grand]

Thanks for all the replies. It seems that no matter what option I have it on- floor & vent, vents, etc- the cold air still blows under the dash. Maybe it's the climate control?

 

[Ranger]

My first Cadillac was a white '71 with a black Vinyl top (later painted white). Bought it about '74.

Second was a light green '72 (I think it was called Willow). Probably bought it about '76.

Red '73 Eldo Biarritz came next

 

[centaur]

Actually my '71 Deville had Automatic Climate Control.


Not entirely. The dual zone was electronic, but I believe, as the diagram showed, the rest was still vacuum.

So on the cars from the 80s and earlier, like your 71 DeVille wasn't that auto climate control an option?

 

[Ranger]

Pretty sure it was a standard Cadillac feature, but I wouldn't swear to it.

The mode was manual, but the temp control was auto. Similar to what we have now, but controlled with a wheel and not quite as sophisticated.


This is from a '71

This is from a '66