1997 Buick Riviera heats only one side

there is either an electric or vacuum motor that moves a door undre your dash. It is either not working or stuck. sometimes if you move them by hand that takes care of it. you'll see a rod connected to motor like just see if it moves one way or te other. LOok carefully as you may have a vacuumline disconnected or leaking.

Thankyou for your reply. It was a fan door motor under the dash, infact there were three motors lined up all on the drivers side from top to bottom and they were all electric. I went to a auto parts store and they said it would cost about $189.00,and they would have special order it. I then went a G.M. junk yard and the cost would be $40.00. I ended up at a you-pull-it junk yard ,took a fan door motor out of a 98 buick park ave. for $4.00, I don't think they new what they had. Now I had to find out witch motor of the three under my dash was the bad one. I took one motor off at a time and replaced it with the new motor and worked the heater buttons untill I got heat on the drivers side and found the bad motor. The bad fan motor was the middle one and I now have heat on both sides of the car. Thanks again [quote:fbc8034b10="hmac300"]there is either an electric or vacuum motor that moves a door undre your dash. It is either not working or stuck. sometimes if you move them by hand that takes care of it. you'll see a rod connected to motor like just see if it moves one way or te other. LOok carefully as you may have a vacuumline disconnected or leaking.[/quote:fbc8034b10]