B0249, dash noise, climate control part replacement procedure

Ooookaaaay! Although I do have a shop manual, here are the pictures from Sewell Cadillac in Grapevine, Texas. They were given to me by Danny in parts for my 2001 DeVille and should be valuable to anyone who has similar trouble.
I went to Sewell today to get the paper copies and also had the service manager listen to the sound. He said right off that it was the "actuator", but this drawing shows several of them. There are two #7s and one #18. So I don't know which one to attack.
At the moment, I think that the doors visible through the two A/C vents are involved, since they are flat horizontally and don't seem to move.
My plan is to go underneath the dash on the passenger side and pull the connectors to first #18 and then #7 and see if the noise stops. That should tell me which of the three possible actuators is involved. The other #7 is a possibility at the moment.

Does that sound like a plan?

BTW, the #7 part costs about $135 at the dealer.

Well, I ain’t done, but I know more than before. I had to ask the question about pulling the power wires on the different components because, let’s face it, computers are incestous. No one talks about it, but it’s true.

So just because I find out that a particular motor without power stops the noise doesn’t mean that there isn’t some kind of hidden relationship in some master module somewhere that is not seeing what it wants and causes the problem because there is some sensor somewhere that has malfunctioned.

I had to quit for the day, but if the method I used of pulling the plugs on the different actuators is a good one (?), then the one that stops the noise is the one on the left: #47. It has some kind of bracket associated with it. And I don’t see right off how to get to it, although pulling the dash doesn’t seem to be the way to do it. There is a plastic duct in the way, and there I stopped.

Thanks for the response Ranger. I hope I’m going the right way and not misinterpreting “the computer”.

Re: B0249, dash noise, 2001 Deville climate control part replacement procedure

Well, if someone wants to chime in, I'd appreciate it. I've started working on this project again and got scared. The gizmo that started it all is called a "Mode Actuator", and it is located high on the driver's side of the a/c duct assembly. The picture I've included in this thread doesn't seem to be the same system I have, but the part I'm trying to replace is #47.

Thus far, I've gotten one of the bolts off and part of the second. But this is so difficult, that I stopped, because I’m not too sure how I will get the new assembly back on.

There is a heating duct that is in the way. So I looked in the shop manual, and found they wanted me to remove something called the IP Carrier. If I’m reading correctly, this would require removal of the steering wheel and all kinds of things. Great fun!

I can see the advantage of this, because you can really see the thing I want to remove, and get wrench clearances and everything. But of course I don’t want to do that at all.

At the same time, there are these three screws that have to go back, and, most importantly, there is a cam plate that has to mate correctly with the followers that control the duct doors. With the visiblily that I have, I’m not at all sure that I can do this.

So: has anyone really done this? I can’t get my hand in the space allowed very well at all. I think that I can get the old motor off, but putting the new one back looks scary.

Well I fixed the car. It took several days. I doubt that people will like my solution, but the only thing I have now is an IPC B0420 code. It’s probably the little temperature sensor that goes on the duct that I cut off with a saber saw. Pretty direct, no? I thought I’d just say it outright.
I do have some tips and other information on the servo motor for the louvers. The one I replaced was high on the right wall of the driver’s side of the middle console. The shop manual said I should just pull the carrier. I bet they had a good laugh about that when they wrote it.
The duct I cut off could have been made to be detatchable, but noooooo!!! And worse, for the rest of you, the new motor I bought could not be separated from the cam plate and the bracket. The motor I took off had a metal spline that pressed onto the cam plate. But the new one, the one with the $3 GM cost reduction built in had all plastic, probably sonic welded parts. I tried to pry the motor off, but stopped when I saw plastic deforming around the screw driver blade. I guess they thought all one had to do was to take the carrier off to fix it, so why not?
When you cut the duct off, things are pretty clear. But I still had to understand the positions of the cams and their relationship to the motor.
I talked to Cadillac before I did the job, and they said they wanted $650 labor. That meant that they didn’t pull the carrier and the mechanic I spoke to explained a couple of tips also. One was to set the louvers so that the cam followers were in the position they should be to make all of the air come from the dash vents. Then, with the motor in your hand and powered up, you set the control on the dash to the “only dash vents” postion. You have just syncronized the mechanical and the electrical components.
I painted the end surfaces of the 4 (four) bosses for the screws white with WhiteOut so I could see them clearly. I made little hooks out of bailing wire and lashed the other ends to things like the crudely cut slots and cracks I had cleverly made in the plastic duct, so the cam followers would stay in place when I tried to engage them, the tracks in the cam plates, and the 4 (four) hold down screws for the inseparable motor, camplate and bracket assembly at the same time. In a place that was not easy to reach either. When I could see that the bracket was going to screw down, I pulled the wires out and listened to hear if the louvers fell out of the tracks. No sound meant that all was well.
Oh, I forgot to say that the follower arms that engage the slotted arms that actuate the louvers can fall out and hit you in the eye, so wear safety glasses. After a couple of dozen times, you get good at putting them back in. And one more thing, the bottom lever acts like it won’t move unless you have the rearmost lever in the correct place. All that has to happen at the same time, and you have to breath too. The front lever hardly moves at all. Still another: you really don’t need a rachet much. You can use the extensions and universal like nut drivers.
If GM had only listened to people like me…. I’ll use Bondo and duct tape to make a sleeve to fit the neck of the duct into, and design it to detach when I want to take it off. Like it should have been in the first place.

I don't have any pictures either, but I tried to explain the way you calibrate the motor and set the followers in the above post. You can start reading from here:


"I talked to Cadillac before I did the job, and they said they wanted $650 labor. That meant that they didn’t pull the carrier and the mechanic I spoke to explained a couple of tips also. One was to set the louvers so that the cam followers were in the position they should be to make all of the air come from the dash vents. Then, with the motor in your hand and powered up, you set the control on the dash to the “only dash vents” postion. You have just syncronized the mechanical and the electrical components."

By the way, I really did cut the duct off with a skill saw, and have had no trouble or codes since. At the dealer, the mechanics develop their own techniques for doing this. I never found out the details, but it's one of the things they just "know". Without cutting the duct, I really have no idea how else to do it.

"Good Luck".