Intermittent Motor Acceleration Sound at Low A/C Fan Speeds

Hello everyone. Have a 2024 4Runner TRD Off-road with 1300 miles. While driving, every 20 seconds or so, I can hear a motor acceleration sound for about 2 seconds, but there's no noticeable increase in airflow from the vent, and the sound cannot be recorded. This only happens while driving and when the AC is on and fan speed is set to low, 2th, 3th. The sound is not present at low speeds (<10 mph) or when the car is completely stopped. I tried replacing the blower with an aftermarket one, but the sound persists. Both the cabin air filter and the blowers are very clean. Is this sound normal? Does anyone else have this experience? Thanks!

 

I bet the AC compressor is kicking on and the load is drawing enough power to slow down the blower then letting it speed up when the compressor disengages until power stabilizes. It's a 24 though so have the dealer inspect it.

 

I'll never understand why someone with a brand new vehicle wouldn't take these issues directly to the dealer. And why would you install an aftermarket blower? I would be surprised if the dealer will honor any warranty work due to that alone. SMH...And, I agree with @whippersnapper02 that it has to do with load on the compressor, which is not normal.

 

Do you have ventilated seats and rock back on forth while driving?

 

Thank you very much for the insight!

 

Had a bad experience with the dealer before, so I am trying to avoid them if possible. I used the aftermarket blower to see if blower was the issue, but I’ve switched back to the OEM one now. Thanks for the advice!

 

I don't have ventilated seats, but my seats don't make noise so far.

 

It is just your AC compressor doing its AC compressing thing. Speeding up and down depending upon the load and temperature.