Clicking noise when opening driver door or rolling driver window down?

Hello! I’m new here but I have the truck listed above 2500 Cummings turbo diesel. After the mechanic put in transmission cooling unit, when I open the driver door, I hear a rhythmic ticking along with alarm beep (occasionally) coming from the dash. When I close the door, it stops. Key in or out of ignition, it doesn’t matter. Also, once the driver's window is down, I can hear the clicking. It stops when the window is up. I have checked all blend door actuators except the SOB behind the HVAC system closest to the firewall. All working fine. I’m at a loss! Please provide insight!