NO LONGER MAKING HUM -- UPDATE AT END...

I took our 4Runner in for new tires this morning at a nearby Firestone. When I drove out and finally used the fan and A/C, I noticed an odd sound. Unfortunately, I was too far away and now had our 3 year old daughter, so I couldn't go check in with them.

The sound is a loud hum coming from the blower assembly (?) down by the passenger foot well. You can hear it regardless of running the regular fan (no-A/C) or running A/C).

There's also an electrical harness pin (not sure what else to call it) that is disconnected. I never noticed anything hanging down before, so I'm wondering if it's always been disconnected, or if it's recently dropped from something.

Here's a video that'll show you the sound, as well as the disconnected pin.

Video Link <- audio drops out at the end, not sure why

During their overall check of the 4R, they took out my cabin air filter to check it and it was pretty full of junk (my bad) and I declined them installing a new one, opting instead to put one in myself. They reinstalled the old filter without knocking out the leaves and junk, and I'm wondering if it's possible something dropped down into this blower assembly.


UPDATE:
I removed out the blower motor from the assembly in the passenger foot area. It was really easy to get out, just three screws and removal of an electrical harness plug. The blower motor dropped down easily, and I made sure it was clear of debris, as well as the area it installs into. I didn't find anything, nor did I find anything leading up towards the cabin air filter. So assuming the worst, I came in to price check them (part 87103-60400, anywhere from $75 to $125).

Anyway, I went out to reinstall it and see if there was a change... and the sound was gone. I drove out of our neighborhood (pretty bumpy roads, wondering if I'd jostle something out of alignment again) and onto a couple major roads (55mph). I came back into our neighborhood... and the noise never came back.

So I'm thinking there may be a bearing that might be going out within the motor... and with a trip coming up to North Carolina in the near future, I'm thinking I may order a new blower motor and have it tucked away during our drive ---- just in case.

-Joel

Hi Joel,

I was looking into you described trouble. Now I haven't been out to my truck, but it looks like you could be missing a blend door/panel. The fact that you can see the blower tells me that somethings not quite right! We have an option of circulating indoor air; which does not allow the hot outdoor air to enter the cabin when the ambient temp and humidity are at unacceptable levels.

And then if the outdoor air is cool, like 60 Deg F, the temp control will bring in fresh air instead of running the compressor to minimize fuel consumption (Free cooling)! And, the system does sound MUCH louder when recirculating indoor air! That harness connector looks like it connects to something that's not even there!

Now, I am a commercial/Industrial A/C technician, but I don't wanna say for absolute certainty that a panel is missing, but I can see the blower wheel, which has no way to pull the air in from the outdoors, cuz there seems to be no way to close off the constant indoor air it's pulling through the blower! I know I could be wrong because I can't see the whole blower case, but...

I'll try to find out what that harness connector with a Lt GRN and RED or PINK wire goes to! 'Best to you',

rig

Thanks @rigtec and @Old Red . I appreciate the help.

I was the one that removed the plastic covering by the foot well. When I heard the loud hum, I tried to see if I could get to where the hum was. The plastic covering comes off fairly easily with three little snap pins at the front. (Reassembly is just as simple.)

I am concerned about the wiring for the LED module. Maybe I inadvertently pulled it out when I removed the plastic foot well cover?

@Old Red , I didn't see a link to a thread. If you share again, I'll definitely take a look and see if I can figure out what's going on.

We're headed out for an outing this morning, but I'll get back under there tonight and take a look when it's not sweltering hot.

-Joel

@GreyhoundGuy what model Runner do you have?


Sent from my iPhone using Tapatalk

Sorry... that used to be in my signature, but I guess I deleted it out. It's a 2010 Limited. I'll go put that info back in.

Great post @Old Red !

...and yeah, the system (Climate Control Automation) does decide; based on outdoor "Temperature/Relative Humidity", whether to utilize the outdoor air to regulate the indoor air quality, or if the OA (outdoor air) quality is objectionable! Based on these factors, a calculated decision is made which is the most economical/effective to use (mechanical cooling or FREE Air temperature control! 'Best to you',

rig

@Old Red , thanks for that post. Page 2 showed exactly what I'm looking at... and what I need to replace. Here's a copy of the post that shows the module I need to replace.

This isn't an image of the one from my Runner, but it's exactly the part that is having problems. And I don't want to blame the folks at Firestone because I don't usually drive at night, so I have no idea if this is a recent or old issue... and in terms of problems, it's pretty minor.

I'll see if I can get one from the Toyota dealer in town. They're a pretty good dealership, and the parts folks have never let me down.

Thanks again for the great link, @Big Red . I really appreciate you digging to find that for me.

-Joel

Hi @GreyhoundGuy ,

As promised, I took a very close look at my 2012 LE this afternoon, just to get a real sense of how it's set up. I removed the bolster airbag trim panel to see, 'up close', what I was looking at in your photos! Well, good news... the RED and BLU wires are only there as a power supply for the foot-well light, that's it!

Also, I thought that I could see the blower wheel inside of the volute on your truck, but I was (gladly) Wrong! What I was seeing was the blower motor housing from the rear which is sealed; no air by-passing the return air duct! I cycled the Fresh Air intake and the Indoor air recirculate mode, and I found not a great deal of change in the sound levels; almost indistinguishable!

The biggest difference was the amount of air movement near the passenger side return plenum, below the glove-box! If the noise is still there, can you describe it's sound e.g., a squeak, grinding sound, rattling, vibration, buzzing...etc? I'd still like to help out! 'Best',

rig, cheers

Interesting thread ... thanks for the info!