What is causing a clicking sound in my dashboard when i turn on the power? on 2007 Ford Mustang

when i turn on the power there is a clicking sound coming from the dashboard that only lasts about 3 seconds. the car starts up fine and there are no other problems or noises.

It could be a defective air control door gear set in your climate control or any number of relays. Best to use a stethoscope to precisely locate EXACTLY where the noise is coming from and then deal with it.

here are some shops for some help: