AC/Heater Vibration/Noise

I tried researching my particular AC/heater vibration/noise since there are so many threads on the issue, but I couldn't find anything relating to my issue.

First off, my AC/heater work great despite the weather being in the triple digits where I live. Low, medium 1 & 2, and high all function properly in regards to cooling/heating. My issue is that when I put the AC on medium 2 and high, I get a low rumbling noise, which increases from medium 2 to high, that I can also feel in the steering wheel and foot peddles. I pulled out my AC blower to check for debris or damage and there was nothing. Additionally, I turned on my AC blower while I had it out to check if the noise was coming from it, which it wasn't. I also popped the hood and listened for the noise under the hood, which also wasn't the issue. While in the cab, it sounded like the rumble noise was coming from somewhere behind the location of the AC blower. The noise is faint, but still bugs me and I'd like to address the issue. Any suggestions would help.

 

The air inlet door is behind the blower?
Maybe it is “loose”. Does it make the noise with the recirculate button ON and Off.
And does it do in all modes - floor, vent, flor/vent and defrost?

Here is a diagram of the AC components

(Provided by Jimmyh: https://www.tacomaworld.com/threads/servo-motor-clicking-how-do-i-get-it-out.506209/#post-15841615)

 

I did have a thought that something might be loose based on the rumble noise/vibration, I just wouldn't even know where to start looking. I also just tried it with recirculate on and off, as well as all modes, and nothing changed.

 

Bump if anyone else might have some ideas. I am stumped on this one.

 

Just asking..
Is this with the truck standing still, not driving it ?

You said that this noise happens in the "AC mode"... Did you try this in the "heater mode"????


I use a 3/8 chunk of tubing to hunt for noises, pop one end in your ear and move the other end around to hunt for noise.
Also get a second person in on the act...Don't help them, just ask them "where do they hear the noise?"

 

It happens driving or parked and with the engine running or not running. Happens with heater as well as every mode. I popped the hood, while the fan was running and the truck engine off, and I couldn't hear anything under the hood. Sound/vibration seems like it's coming from somewhere behind the AC blower.

 

Sure sounds like the blower motor...
The blower's squirrel cage rubbing on something inside the ac/heater box?

 

My bad. I originally rushed my judgement on where the issue was coming from due to the 110 degree weather that day. Thought it was coming from behind the blower motor. Took a little more time this morning, during cooler weather, and pulled the blower motor out again. Found all the issues are with the motor. Ordered a replacement.

 

Great