Climate control only blowing cold air

Hi All,

My car is not blowing any hot air through the vents. Temperature is set to high/correct setting. I got my car looked at and the mechanic said the car has the proper coolant level, no air in coolant system and nothing is leaking. Hoses going to the heater core/through the firewall are hot also. He's pretty sure it's the blend door actuator. I am pretty sure it's that as well because for the past year I had been hearing clicking under the dash. I found one actuator and it is the driver side foot-well but I don't believe it's the one that controls hot or cold air. Does anyone have a chart that shows where all of the actuators are located? I'd like to know where the one that controls the hot/cold air from coming in is located before I try tearing apart the dash. Thank you.