High whining noise

Since I’d recently spent a couple of thousand dollars on repair on my 2010 Prius, I decided to have the interior detailed, too. On November 12, the company picked it up at my home, cleaned it, and returned it that night.

When I went to look at the interior I heard a strange, high whining noise. The Prius had been off for at least an hour at this point. No lights had been left on, no engine lights were on—just the whining noise. It seemed to be coming from somewhere between the console and the hood. Later that night I could still hear it just walking by the closed car.

Since it was dark, in the morning we disconnected the 12v battery. Instantly the sound disappeared. We reconnected the battery.

The next morning the battery, which was only a couple of months old, was completely dead. Strangely, I could still hear a version of the original whining, but this time it sounded mechanical rather than electronic. I opened the hood and, just to do something, I tightened the cap on one of the liquids. Instantly the noise stopped.

When we tried to charge it with a battery charger, the read-out would not rise above 75%, no lights came on, and of course the car would not start.

I’m thinking the only option right now is to have it towed to another town where there’s a Prius service center. Any ideas?

 

Thank you for your reply! The 12v was purchased in August 2021.

I wrote to the company about the engine bay and am waiting for a response. It doesn't look like they cleaned it. It was either the brake fluid or the reservoir closest to it, and I'm not sure what that is. When you have complaints after detailing, is the company in any way responsible?

Thanks again.