got a strange problem with the heat in my deville. started about a month ago. when the heat is on, the passenger side defroster is hot. the drivers side is luke warm, and the heat coming out of the floor discharge is less than warm. doesn't matter where the temp seclector is set. no codes are showing, and the coolant level is fine. any ideas ??!!

 

I hope you get an answer because I have the same problem with my 94 deville. I keep meaning to dig into it, but haven't had the time yet.