you'll have to see why the actuators aren't working that directs air in the heater. it could also be a control becaue tis probably has automatic temp control. pic enclosed.

Can I access this from the under side of the dash. I have currently taken some molding off and have located an air leak up by the fire wall. Not sure what I have found

it kind of looks like this may be on the drivers side so maybe looking up by gas pedal youmay see it to repair it. as afar as air leaks it cold be just foam worn as the car is 13 yrs old now. Normally you have to pull thedash out to fix heater box problems but you may be able to reach it.