Jim,

You're welcome. This is a common question this time of year for folks new to life with a W126 - I asked it two years ago as well. Just close the lever on the center vent to cut off the cold air in back (unless, of course, it's your mother-in-law who sits in back )

jlc

__________________
Jeff

'87 560SEL 267K (177K on motor) Blue/Blue
'98 Buick LeSebre 60K (wife's car)
'56 Imperial Sedan 124K
Past Cars:
'67 Dodge Monaco 130K (Sold)
'87 Chrysler 5th Ave 245K and going strong (sold)
'73 Plymouth Satillite 175K (sold)
'96 Chrysler LHS 80K (totaled)