Where are the the heater core and the control valve on this vehicle?

I am not sure if this car has a heater valve, so follow the heater hoses up to the heater core to locate it. Often the climate control head goes out on this vintage Mercedes, so that is something to check. As far as dealing with the heat control door operation, that can be a huge job, you have to remove the dash to get full access, which is a 10-12 hour job for a Professional Tech.