why would only the driver side blow heat through the vent and defrost and on the passenger side is blowing cold air?
a diverter or servo motor is malfunctioning~ will have to research on part numbers and mechanisms if you need~
are you hearing any hissing? possibly a vacuum hose is cracked or fallen off~
my 1994 deville was the opposite - warmish on passenger side defrost and cool on drivers side. Turned out to be a problem with an inexpensive plastic " T " that (on my car) is top and center near firewall under the hood. too much hot water was going thru the bottom of the T and not enough going thru firewall to heater core. $20.00 part fixed it!
My 2000 Cadillac Seville sls blowing cold air on driver side but passenger side is blowing hot air Any reason why my driver side is blowing cold air when heater is on?
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