Clicking noise under passenger side dash, headlights flash when off?

Sounds like it maybe a faulty relay or module malfuntion..

Tests/Procedures: 1. Access the driver's blend door actuator, located to the left front of the center console, just under the dash. 2. Put your hand on the actuator, if this is the clicking noise you are hearing, remove the actuator and verify the door is not sticking, if the door is not sticking, replace the actuator. 3. Note, it is not necessary to remove the dash to replace the actuator. as far as your lights flashing that could be another issue.

agree with mech are mobile poss door actuator