The factory shop manual for my 2k shows 4 "doors" in the under dash unit so
there are at least 4 vacuum actuators that push or pull each of these. They
are:
Temp blend air door
Panel defrost door
Heat defrost door
Recirculating air door
I believe all of these are located on the outside of the unit so that
disassembly of any part of the unit isn't necessary to access the faulty one.
However, working under the dash is akin to a root canal without anesthetic so
I'd take it to my dealer.
My truck has a V6 and far as I know it does not have a separate vacuum source
pump. Vacuum is just taken from the intake manifold. I believe the only
vacuum requirements inside the cab is for the AVAC unit so you can trace from the
engine side of the firewall the HVAC supply and follow it to its source
This archive was generated by hypermail 2b29 : Fri Feb 06 2004 - 11:47:09 EST