High-pitched noise from glove box area - Cause?
- Thread starter Chaz526
- Start date
Register to hide this ad
zerowkul98
New member
I think the blower fan is behind there. When the noise occurs, is the fan on at all?
Chaz526
New member
Update: unplugged wiring from the blower and the tone still remained. Unplugged another connection near the motor (resistor maybe?) and that too didn't work. I'm stumped.
In the cabin, the tone is very high pitched. Under the hood, there is a lower pitched noise but it doesn't seem isolated like it is in the cabin.
I'm not sure if the tones are related, or if the under-the-hood noise is just normal when the ignition is turned to on but the engine isn't started.
In the cabin, the tone is very high pitched. Under the hood, there is a lower pitched noise but it doesn't seem isolated like it is in the cabin.
I'm not sure if the tones are related, or if the under-the-hood noise is just normal when the ignition is turned to on but the engine isn't started.
I've had this happen about 4 times to me before I was able to consistently remember it's my water bottle slowly leaking air out of the mouthpiece.
Doesn't help you, just thought it was funny.
Camelbak Podium? Happens to me too.
That's the one!
nevada
Senior Member
i believe our HVAC is controlled by vacuum, perhaps one of the vacuum motors is bad and leaking slightly. sometimes a leak can flutter, and cause a high pitch sound. maybe try to find the main vacuum source at the engine, and disconnect it.
BlackWorksInc
New member
The ECM? That's weird, there shouldn't be much of anything causing a high pitched sound from the ECM. I mean there's transistors and capacitors in there, but its not getting high amperage/voltage so I don't see why it would make that noise (no cooling fans either.)
The ECM is the large rectangular box bolted near the HVAC blower motor assembly. When you take out the glove box you can see it sandwiched between the A-pillar and the HVAC assembly.
This is pretty much shows you how to get to it:
http://www.toyota-4runner.org/4th-gen-t4rs/156776-replacing-re-circulation-actuator.html
Post Note-
Perhaps it is the recirculation air door actuator?
The ECM is the large rectangular box bolted near the HVAC blower motor assembly. When you take out the glove box you can see it sandwiched between the A-pillar and the HVAC assembly.
This is pretty much shows you how to get to it:
http://www.toyota-4runner.org/4th-gen-t4rs/156776-replacing-re-circulation-actuator.html
Post Note-
Perhaps it is the recirculation air door actuator?
Last edited:
Chaz526
New member
Thanks - this has been very helpful.
I thought it was the ECU/ECM because I've seen other posts claiming replacing it solved the problem. My thought is, like you led on, a capacitor could be whining from within.
As for the actuator, does it have the ability to make a constant, non-fluctuating high-pitched electronic noise?
Is there a way I can cut power to the actuator to see if the noise goes away? I'm assuming there's a fuse, but I've pulled a few thinking I was cutting power to the blower motor but still heard the noise.
BlackWorksInc
New member
Pull the plug on the actuator, use the guide to find it. 
BlackWorksInc
New member
Weird... Well I mean you could live with it or replace the ECM. That's the first I have ever heard of a 4th gen ECM making noise though... how weird...
nevada
Senior Member
I found the source of the high-pitched noise. It was gone when I pulled the power to this device. I'm assuming it's the ECU.
If so, what are my options [MENTION=66389]BlackWorksInc[/MENTION]?
the noise stopped when you pulled power, but is that where it was coming from?
just about every electrical component is controlled/powered but the ECU, so pulling power from that, also cuts power from everything else...
Chaz526
New member
The sound emanates from behind the glove box, behind which I unplugged just about everything. The noise never went away until I unplugged the ECM.
Does literally all the power flow through it? That doesn't seem right to me.
