My truck is a 2006 Dakota 4.7 Liter club cab with all the goodies,
electric door locks, keyless entry, etc.
My problem is that sometimes when I change either the fan speed
or the temp. range, I get a sound like a relay or solenide chattering from under the dash. The sound may come from directly in front of the steering wheel, and other times from the passenger side below and in front of the glove compartment. At times, when I first start the engine it happens.

At times I can stop the chatter by turning off the blower or moving the temp.
control up and down, or even changing the setting for the air comes out.
(Floor, Defroster, etc.)
Anyone know a fix for this?

 

Is it an ongoing "chatter"? I know that whenever I turn mine on or change the vent selector, I can hear an electric motor (this sometimes happens when I start the truck too), but it only sounds for about a second, maybe two.

If it is a flapping sound, in my old ('96) Corolla, I got a piece of paper stuck in one of my vents and it about drove me crazy. About 4 months after I started hearing it, it came out of its own volition (thank God).

 

Hey Jedi, Thanks for the reply. I believe this problem has to do with the calibration of the driving units for the HVAC system. I understand that everything is driven by the computer, but don't know what mechanical equipment is used to move the various components. The unit (what ever it is). The one behind the dash sometimes comes on when I start the engine, and is much louder than the other unit over on the passenger side, as if it is larger and more powerful. If it happens when I start the engine, I have to shut it down and restart. Even turning the HVAC fan on will sometimes start the chatter. Other times it'll go for days with no problem. It's pretty strange.

 

There are little electric motor things for the flaps. Just two or 3 torx screws hold them onto the hvac box. I removed them when i tore my heater box out to replace a heater core. THose could be the issue. They have no calibration that i know of. Its all computer controlled. YOu dont even have to put the flaps back at the same exact angle because they are computer controlled. I did have 1 extrra flap thingyyy when I put my box back together, not sure where it went LOL. Im thinking about taking my dash back off to replace that properly as i only replaced the heater core in a hurry. This time, ill also replace the condensor thing for the ac in the dash at the same time and the resistor and maybe even the blower motor so I wont have to replace those parts again in the future.

 

Thanks for the reply Jeremy. I guess it's possible that the problem is in the computer.
However, the computer has to have some sort of feedback to tell it when to stop the motor. Maybe the motor torque is the feedback. Here is another crazy thing that happened yesterday. I was on my way to the market. While stopped at a traffic light I changed my radio from am to fm, and the clicking sound from the HVAC started. I shut off the radio and it quit.

 

The motors are called Actuators. Idk if that helps you. You dont have to disassemlbe the heaterbox to remove then. But dash must be removed to the best of my knowledge. I put them in different directions. Originally, i was so scared that i messed up cuz i didnt know they were computerized and thought you had to put them in the same way. I brought the box to dodge and they said that it doesnt matter, what a sigh of relief! THose can be causing your issue

 

Hi Jeremy.
I called a dodge dealer over in the next town, and talked to the service dept. about the problem. He had dealt with the same problem before. It will be either a bad actuator, or a broken hinge on a door. He told me to bring it by, and they can test it with the testing equipment they have. No charge for the tests. The dash doesn't need to be removed to change out the actuators, and He says an actuator will cost around $100. If it is something like a broken hinge, then the dash must come out to replace it. I'll get back to you after I get it checked, and let you know what happened.
Thanks. Bill

 

I didn't remember how much access there was under the dash. I had to remove the actuators to disassemble my hvac box to do my heater core. I doubt the hinge/flap thing will continuously make a noise. They are pretty heavy duty too. There are 3-4 actuators on the box.

 

Let's not hope its the the hinge. Dash takes a couple hours to take off, but it will cost a lot.