Kloines, I think I'm with you... the heater valve is connected to the flap on the heater box.
However, you say the
right side heater flap, but do you mean the
left (drivers) side heater flap (LHD car)? I guess I'll find out once I remove the air "scoop" assembly.
Does one of the lower slide controls on the dash then operate the heater flap, coincidentally operating the heater valve. What is the connection type between the slide cable and the heater flap?
And if I read the Haynes manual correctly, then the other lower slide control simply opens another flap (passenger side) independently of the heater valve.
Am I close?
PS: Cees, a friend of mine (different make/model) does the same thing as you. Since the valve works, and I'm a glutten for punishment, I'ld like to attempt the simply remedy the faulty connection (seems no money or purchase, just time, is required)
Nervious Newbie `68 280sl