Noise behind dash when truck has been off for hours?..

[Curtamous]

So I just bought a 2014 Ram Laramie Hemi 4x4 just yesterday.
Last night while I was getting settled into it with all my stuff I kept hearing a noise in the dash. Sounds like the HVAC blend doors/actuators. (Yes I viewed other posts on blend doors but none mentioned while the truck is off) The intermittent sound appeared to be coming from different areas behind the dash. I do know hvac blend door noise, so pretty sure they are the culprit... but WHY after the truck has been off for hours? The doors were open but wtf?

 

[csuder99]

From what I understand the blend doors are moving when the truck "goes to sleep", or more specifically the cabin comfort module or whatever it is called. When the modules don't see any activity on the CAN bus they enter a low power consumption state. I'd guess you repeatedly woke up the modules, e.g. opening/closing doors, playing with the radio functions etc.. Maybe even getting in and out of the truck triggers occupancy sensors or interior alarm sensors.

 

[indept]

Or it could be one of these

 

[crash68]

I'll second what @csuder99 stated.

 

[Jeepwalker]

If you haven't disturbed the vehicle for a while (it takes about 1/2 hr probably to go to 'sleep') and you're still hearing the blend doors hunt, it might not hurt to pull the codes on your HVAC module.

If for a variety of reasons, if the HVAC computer doesn't detect a full open or full closed position signal from the blend door drive motor/s, the hvac computer makes multiple attempts to find full open and full closed. That might be the 'hunting' sound you hear.

Reasons which could cause that include: Blend door broken off the hinges, faulty motor, damaged or slipping plastic splines, whacky HVAC module. I have a Jeep GC where I will sometimes hear the blend doors make a sweep or two when I'm in the vacinity ...seemingly out of the blue, even if it hasn't been driven in a day or more. It doesn't occur very often or for very long. It has never worn down the battery, even when I've let the vehicle sit at the airport for a full month (which I've done a number of times).

Check for codes first, there may not be a problem.

 

[RLJ10X]

My Wrangler makes all sorts of weird noises for a while after it’s been shut off.

 

[EdGs]

Or it could be one of these


View attachment 485765

That would be a hell of a thing. And, I'm sure there were more baby rattlers than just that one...

 

[indept]

Found bigger reason (than my original post above) for dash noises

https://www.youtube.com/watch?v=L5KxhXxh8ec