Strange Noise from A/C Fans - Is it normal?

I have experienced that also. Always happens when A/C is on full. I noticed that buzzing vibration as well. It has happened since I got the car last year, but A/C is cold and blower is strong. Don't suspect it is a problem, just another mannerism for this car.

 

The air conditioner pump is electric on the Prius (runs on high voltage 200V from the inverter) and is of variable speed. It can therefore run without the ICE running. Usually, in a non hybrid car, the A/C pump is attached by a belt to the ICE and is either on or off (by mean of a pulley if I'm not mistaken).

What your are hearing is simply this variable speed electric pump, and it is probably more noticeable when the ICE is off (something that doesn't ever happen in a non hybrid car).

Its speed will change according to the amount of cooling required, depending on outside temp, cabin temp, requested temp and fan speed.

Its sound may ressemble the one from the brake pump (when you open the driver's door to come in.

Everything is fine.

 

You can unplug the AC fans and check if the noise is from the fans or AC compressor.
At full speed the AC compressor draws 4KW, it will drain the 1.3KWh HV pack in less than 15 minutes, but the ICE will kick in when it is down to the minimum SOC.

 

hey grumpy when i am at the taxi stand and have about 3-4 bars on the bat,i can get about 15 minutes of ac untill i finaly reach the front of the line to get a customer without havin the engine come online haahahahaaaaaaa on the low setting max ac low fan !!! then from that specific taxi stand i get in to a 4 minute drive downsloap that while having the ac still on i fill most of the bat up while coasting on the sweet spot at 80km! thats somethin,thats great,got to love it!!! and i still get 5.5 to 100



the older model prius probably doesent get this sound,because it uses a belt drive for the ac and power steering.and thanks for bringing this sound up because i still havent tried full power on the ac!!! saved me the panic there partner !

 

p.s i actualy huged my taxi today when another cabby asked me what i think of this car!!!! hahahahaaaaaaa nedent put any more into explaining anything else about the car to him!!! haha

 

I thought the older model's had a belt to drive the water pump. But now the 2010 has electric water pumps. I am pretty sure the other prius models have electric steering and ac.

 

The 'Classic' Prius (2001-2003, model NHW11) has electric power steering, but the A/C compressor runs off the accessory drive belt. The engine coolant pump is also driven from there.

The 'Iconic' Prius (2004-2009, model NHW20) has EPS and variable-speed electric compressor powered from the high-voltage battery. It still has a drive belt that now only runs the engine coolant pump.

On the newest model (ZVW30) the compressor is still electric. The engine coolant pump is now electric and the drive belt has been removed. The pulley on the end of the engine crankshaft is still present as it helps to balance the flywheel at the other end.

The earlier models also have auxiliary electric coolant pumps to pump hot coolant through the heater core when the engine is stopped. I imagine that one pump does both jobs on the new model.

 

Glad I searched the forums before posting. I also have the buzzing/crackle from the driver vent. I haven't listened for the passenger side (safety first ;-) and the middle vents don't make this noise. The sound is low but constant regardless of AC speed, even if very low. I close the vent, noise disappears... open the vent, I hear it again. I thought it was a speaker that was bad at first, because of the crackly nature, but that was definitely not the issue. The dealer told me today it was "normal" but dealers tell you a LOT of things are normal so I thought I'd search around. Thanks to all who contributed info here. Very helpful.

 

The driver's side vent contains the Plasmacluster on the IV and V. That is probably the noise you hear. It's mentioned in the manual.

 

The dealership mentioned that the noise was discussed in the manual but I wasn't able to locate that info. Good to hear it confirmed outside of the dealership though, so thanks for the info!

 

Glad I found this thread. The other day I got out of my Prius to open a gate. AC was on full. I put in in Park and when I got out I heard a pretty loud buzzing sound from the car. ICE was off. Never heard that before and figured the AC might be the culprit. Turned it off and the sound went away. As I changed the AC level, the noise got softer or louder.

Glad this is normal, though it doesn't sound normal to me.

 

And just for the record; the AC compressor gets DC voltage direct from the HV battery. It has its own internal inverter to run the 3-phase AC compressor motor at variable speeds. If you look at the AC compressor you'll see only 2 big DC wires going into it and a smaller control wires. This is for efficiency, one less electrical conversion.

Just techno-geek stuff.... This is such a high tech car !!!

 

Could be if you handed it over to a dealer.
I saw postings of used compressors for not too much.
Looks like a simple install and then the usual freon evac and charge, which any small AC shop could do.
But this compressor has no external seal on a spinning input shaft. Could be one long life component!
Think home refrigerator...

 

My Prius C2 (2012) has the same problem: a high pinch noise with the sound buzzing from an electrical transformer. Such noise occurs whenever the A/C is turned on and immediately disappears as the A/C is off. Also, the cooling fan will turn once the A/C is on and stops when the A/C is off.
At the moment, I could not be for sure whether the noise is from the A/C compressor or from the cooling fan.
What is your opinion?

 

Hey guys my A/C compressor was making a very loud humming louder then usual so i replaced it. I got the compressor from ebay tested and all i put it in myself. My A/C has been working for a week and now all of a sudden it does not blow cold air and is making a weird noise through the A/C vent does anyone know what this can be?

 

It is a hissing noise through my vents