92 Buick Park Ave Heater Control Air from Defroster and floor all the time

Anyone have any ideas? air comes from the floor and defroster all the time regardless of selection. Everything appears to work normally. This car has electronic controls, and I
have entered the diagnostic mode and found no fault codes, and any further troubleshooting thru the diagnostic mode it isn't much help without a book telling me what all those different numbers mean. Anyway I have checked the vacuum hoses and anything else I can get to and everything seems ok. Can anyone tell me what exactly control the air discharge. Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
There are actuators that cotrol the airflow in the heater core box/ electrical / mechanical. they may need to be replaced
On Mon, 17 Nov 2003 20:20:43 -0500, "Mastermech"

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I had the exact same problem with my '94 PA. I checked all of the vacuum hoses also, but it didn't solve the problem. Then, when I was changing the Master cylinder, I noticed the vacuum line that goes into the firewall to control the heater controls was partially connected (vacuum leak). The car never ran rough. I reconnected the vacuum line, and the controls started working again.
I also found this link to help out. I actually went to an auto-recycler and pulled out the vacuum manifold from another PA just in case. Never needed it. I have since sold the car. If you determine that the vacuum manifold on your PA is bad and want the one I have, let me know.
http://www.imcool.com/articles/aircondition/fix_vacuum_line.htm
Bill
Mastermech wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the link William. That looks indeed like it may be my trouble, I will try to get in there and take a look this weekend and post back.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
FIXED IT!
Great link! Although my trouble wasn't from bad hoses it sent me in the right direction. Turns out that the vacuum hose you mentioned next to the master cylinder was connected but there wasn't any vacuum. The hose connects to a black plastic box. I opened it up and low and behold it was empty. Must be a vacuum accumulator. I sealed it up good reinstalled and presto. Good as new! Thanks again for the input.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.