I just purchased a 1983 300D Turbo Diesel and I'm having problems with the climate control - even with the temperature dial set all the way to cold/blue and the fan off, all of the dashboard vents leak a steady flow of hot air into the passenger compartment. Discovered the problem on last week's family drive up Hwy 5 through 105 degree heat in Redding, CA - even at midnight we were sweltering inside. The sunroof is great but...
Is there a valve or control unit somewhere that might be the culprit here? On our old 1982 240D there was no A/C but we could still keep the temp dial at cold and the master vent lever pulled all the way left to open to get clean cool air from the outside into the passenger compartment via the dash vents. But there is no master vent open/close lever on this dashboard and the temp dial isn't doing us any good. Any and all suggestions would be greatly appreciated.