There's a chirping sound coming from under the hood on the left (driver) side seemingly around the master brake or the electrical connections on that side of the engine. The sound is like a bird chirping that began on most cold starts and lasted around 10 - 20 seconds, then stopped. It's progressed to where on cold starts it lasts for around a minute or 2 and then stops and will sometimes start again as I'm driving. It seems to be getting more frequent. No system warning lights come on, and the car runs fine, brakes good. Any ideas what it might be?