I'm new here (not sure if I'm in the right forum) I'm currently driving a Prius + Seven with just over 300000 km on it. There is this really loud noise coming from the fan behind the radiator or condenser when the AC is on, and I'm standing still. It's on for about 3 seconds, then off for 30 sec, then on again and continues like this. Once I turn the AC off, it disappeares. Anyone knows what this might be? I would post a video, but I'm currently on a phone, and it didn't work.
Seems like the AC fan behind the radiator. I believe it should run continuously when the AC is on. Yours probably has a bad bearing and is overloading a circuit. Replacement is probably in order.
I don't think the fans run continuously when AC is on*; they would come on and shut off in tandem with the AC compressor operation. And if the noise is gone when AC is off, then that points to either the AC fan, or something in the compressor. * @rjparker, maybe I'm just misunderstanding what you mean by "AC is on"?