What is that solenoid noise under the dash?

I never heard it as much as I heard it today. The sound was the sound that the climate control doors make when they are being adjusted.
The reason I'm asking about it, is that today, the car decided to make these noises repeatedly and for no reason, while the climate control was in the "stop" position! It seemed to make the noise a moment after I gave a little throttle, almost every time. It also made a ticking noise that I never really heard because it is so faint (sounds like a relay. Almost like the turn signal, but much quieter). I placed my iphone under the dash to get a recording for me to post (hopefully it works for you guys). That's when I noticed the clicking noise. Since I stuck the phone at the bottom of the dash, I was able to hear all the noises very clearly. I don't remember ever hearing the climate control freak out and change so often. Tonight was the first time I noticed it, and by the time I got home, I couldn't seem to duplicate it. Did anyone ever experience this? Maybe it was caught at just the right temp/humidity for it to alternate between defrosting, and other vents? Let me know what you guys think. I tried doing a search, and found one or two others that sounded like it was the same issue, but I'm not sure, and there was no definitive answer either. By the way, the car is a 2004 360. Thanks!
Image Unavailable, Please Login

 

I took the car out again today and I narrowed down a pattern. It is definitely the damper door servo that selects which vent air comes out of, and it happens when the air direction switch is in auto mode. If I select the vent position manually, it will not make the noise. I also noticed that it only does it when I first start the car. After the car is warm, it doesn't do it anymore. That explains why I never heard it before. It has been over 50 or 60 degrees here and it dropped to 30 degrees abruptly, so I only heard it when it was cold outside with the engine cold. It most likely didn't do it when it was 60 degrees outside. This is my first year with the car, so I have no idea how it behaves in different temps.
The strange part is that it seems to do it if the stop button is pressed and when it's not pressed as well. I also find it strange that the auto vent selection works with the stop button pressed and the system off. I guess an explaination would be that there is still air flow when you drive, and auto mode controls it for driver comfort even when the climate control system is off....who knows..
I'm sure it's not a problem with the car, I'm just trying to figure out how it all works. Or at least how the engineers intended it to work.

 

The ticking is very slight, but if you listen closely to my audio recording above, it can be heard. Do you think that it is the noise that you mentioned that comes from the signal relay?
As I mentioned, it is a VERY slight noise, that is barely audible. When I turn the signal on, it is super loud!
I guess I'll bury my head under the dash next time I drive her (of course not while driving, LOL), to see if I can hear it up close to confirm. I'm still not sure if it always makes the clicking, or if it only does it only when the climate control has a fit, like in the audio recorrding above.
I'm sure it's very easy to replace and fairly inexpensive.

UPDATE:
easy to replace? Yes.........inexpensive? NO
I just looked it up, expecting it to cost about $50, a new relay costs approximately $225! I can't believe it costs that much. If I need the relay, it will be the first penny I spent on the car for a repair, and I enjoyed it for over 6 months and 1,500 miles (almost). I shouldn't complain, it could have been worse!

 

When I first heard it, I didn't bother trying to figure out exactly which relay it was. I haven't used the car since the posts that gave me the idea to listen to the turn signal relay. Once the weather clears up around here, I will use the car again. I'll do my best to isolate the noise source and post the results here. For the people who also hear the faint clicking of the relay, do you also hear the climate control servos freaking out? I'm trying to get some sort of pattern. I have a funny feeling that all this may be totally normal.

 

I looked into the noise even further today when I took the car out for a spin. Unfortunately, I didn't come up with a solution. I did, however, narrow down the behavior a little bit more.

For starters, I looked at all of the linkages and they are fine, as I suspected. Then I started the car cold with the climate control set to auto on both fuctions (dampers and fan speed), but the stop button pressed in (that is the way I always left it the other times when it made the noises). Once running, as it did on the prior days, the damper doors kept changing and the slight ticking noise was present. The ticking is very slight, so I basically have to stick a recorder under there, or my head has to be all the way in the footwell in order to hear it. I then listened carefully for the source of the noises. The solenoid for the damper door was obvious, and I was also able to look up under the passenger side dash and see a white plastic connector moving when the damper doors move. the ticking was harder to locate. I never pinpointed it, but it seemed to be coming from the same area as the damper door fitting. It is not coming from the turn signal relay as some others suggested. Like I said, I was not able to locate the source, so that is still fair game.

I then completed my ride, and left everything on the climate control set the same way for the whole ride. Apparently, as I suspected other times, the damper doors don't freak out after the car is warm, and / or stabilized (I guess the a/c would do the same until the car cools in the summer). I also didn't have the ticking noise once the damper doors stopped freaking out. I put a recorder under the dash just to be 100% sure. I then manually adjusted the damper to the other settings, and sure enough, with every move of the door there was the ticking noise that followed for a few seconds. I repeated this with 100% consistency.

I guess the outcome seems to be that the quiet solenoid ticking is directly associated to the movement of the damper, and the damper set on auto freaks out until the temp in the car has stabilized. This doesn't occur if I manually set the damper door to a fixed position. At this point I have to assume that this is all normal and just weird. If I don't want to hear the freak out, I just have to leave the car with the damper doors in a fixed position. I know others also stated that their cars did this, so it makes me feel a little more confident that it is just a characteristic (flaw) of the climate control on these cars. If anyone can think of any other possibilities, please let me know.