The heat is on all the time in my 450sl. I can change the flow from defrost to floor and lower the temp but there is still flow to the floor. Any help would be appreciated.

I'm not intimately familiar with the SL's, but I'm quite confident that there is a coolant flow valve of some sort in the climate control system. I would be willing to bet that your problem is related to it. Either an incorrect signal, not likely, or a malfunctioning valve.

Hope this helps.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

i think the early r107's use some sort of vaccum pod to operate a heater valve; it's probably stuck in the open position. hopefully someone with early r107's can chime in to verify. i vaguely remember working on one a long time ago

Yes, it's a pink/ black valve in a heater line by the firewall on the driver's side, as I recall. Either the vacuum line is off or the valve is shot.

__________________
1968 230S Automatic, Elfenbein
1975 O309D Executive Westfalia Camper Bus, Blau/ Weiss
1972 280SEL 4,5 Dunkelrot
1966 VW Type 34 "Grosser" Karmann-Ghia
1963 VW 1500 Variant Pearlweiss
1969 VW Variant Automatic, Perugruen
1971 VW Squareback Automatic, Clementine Orange
2001 E320 4Matic Wagon- Our belated welcome to the 21st century! Polar White
1973 280SEL 4,5 Sliding Roof "The Bomb", Dunkelblau.