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.