where are the blend doors located On My 1997 Buick LeSabre?

Question

HOW DO I FIX A VACCUM LEAK THAT CONTROLS MY A/C DUCT DOOR ?

Answer 1

Blend doors are inside the a/c ductwork behind and under the dash and are operated by vacuum diaphrams---you'll have to listen for a constant hissing noise as you change the mode switch from heater to defrost to bilevel---track down the source of the hissing to find the vacuum leak---leak could be in the vacuum lines or the a/c control switch on the dash heater controls as well as the vacuum line running from the engine compartment to the a/c control switch or from the engine to the vacuum storage ball under the hood.. A good shop manual that shows how to disassemble the dash and components would be very useful if not necessary. Eautorepair.net has online access for a fee or Alldata.com---parts stores and libraries have Chilton or Haynes book manuals although they may not be as detailed.