Climate control problems
 

On my 83 300TD the push buttons for the climate control started acting up last month. Here is what it does, when it is blowing heat, the only way it will blow on the floor is to have the bi-level button pushed. If you have the econo or normal button pushed, it blows hot air through the dash vents. Also when either one of those two buttons are pushed the car does not want to shut off nor does the door locks want to work. Does this sound like the push buttons or the switch over valve? I think the servo must work for the floor because when the bi-level is used it blows on the floor and the locks work and the car shuts off fine. I have tried the search and did not find what I was looking for. What would your opinions be?

Because of the door lock problem and the shut off problem, I'd say one of the vacuum actuators has a large leak (split diaphragm). Test with MitiVac at the switch gang, under the passenger side console tunnel at underdash area.

Thank you for your response.