93 LeSabre Airflow Problems - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-31-2014, 02:48 PM   #1
Junior Member
Thread Starter
 
Join Date: Mar 2014
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
OwenL is on a distinguished road
Default 93 LeSabre Airflow Problems

Hey folks. I've got a '93 Buick Lesabre, and among other issues, the front vents never have airflow; just the Defrost and floor vents. When pressing the 'vent' option on the controls, nothing happens, airflow just stays at those two vents.

I've checked the engine bay for vacuum leaks; all the connections are good, nothing is disconnected, there'* good vacuum when I disconnect the line from the vacuum tank. I also went into the cab on the passengers side and disconnected the 4 colored vacuum lines from the control unit they connect to and individually tested for vacuum; they were all good.

Most people say that when there'* a vacuum leak, the system defaults to Defrost, which would make sense. But as far as I can tell all vacuum connections are fine.

There'* a motor in behind the glove box that, I assume, is what changes the temperature (when the temp on the controls is changed, the motor opens or closes), and it functions fine. It switches between hot or cold smoothly. Is there another motor that control the front vent doors?

It'* also worth mentioning that the climate controls function fine; air speed and temperature sliders work fine and the airflow responds, it just doesn't want to send air out of the front vents.

I'm pretty well stumped, as I've tried everything I can find. Any suggestions?

Thanks!

Last edited by OwenL; 03-31-2014 at 02:50 PM.
OwenL is offline   Reply With Quote
Old 03-31-2014, 02:59 PM   #2
Junior Member
Thread Starter
 
Join Date: Mar 2014
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
OwenL is on a distinguished road
Default

Here are some pictures. The first is of the motor that controls temperature behind the glove box.


Third is what kind of climate control it has, if that helps at all.
Attached Thumbnails
93 LeSabre Airflow Problems-uqodz5k.jpg   93 LeSabre Airflow Problems-sgeysbn.jpg   93 LeSabre Airflow Problems-sakfnft.jpg  
OwenL is offline   Reply With Quote
Old 03-31-2014, 03:54 PM   #3
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

not being that familiar with the car, i would guess there has to be another actuator for position just by having buttons instead of a dial or slider
jwfirebird is offline   Reply With Quote
Old 03-31-2014, 04:54 PM   #4
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

A faulty HVAC head unit will also default to defrost.
2kg4u is offline   Reply With Quote
Old 03-31-2014, 05:25 PM   #5
Junior Member
Thread Starter
 
Join Date: Mar 2014
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
OwenL is on a distinguished road
Default

I think I've narrowed it down to two things. Either the primary climate controls, or the vacuum valve Solenoid.

I applied vacuum to each hose; defrost, vent, bi level and defog. When vacuum was applied to each hose, the airflow change was obvious and functioning as normal.

When having everything set up normally, when pressing settings on the climate control I can feel the solenoids in the control valve opening and closing; there'* an audible noise and I can feel the vibrations. But it doesn't change the airflow as it should, especially when setting it to 'vent' (it literally does nothing)

The climate control is intermittent; sometimes it'll turn on and other times it will turn off. After replacing this, would the only thing left to replace be the control valve?

It seems to me that it'* either the main control or the valve. I have to replace the primary climate control anyways, so it seems it'll be easy to figure out what comes next.

Any other input would be great.

Thanks!
OwenL is offline   Reply With Quote
Old 03-31-2014, 10:42 PM   #6
Senior Member

Certified GM nut
 
Tech II's Avatar
 
Join Date: Feb 2014
Location: Worcester, Ma.
Posts: 2,142
Thanked 778 Times in 608 Posts
Tech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond repute
Default

From your description, it sounds like a vac solenoid box which controls the vac to each vac actuator....you will need a schematic for the solenoid box harness, and check for power in the harness circuit, that corresponds to heater, vent, bi-level, etc.......Since you have a vac source, if the harness voltages check out, you need a vac solenoid box....if they don't, you need a control head....

I can't remember if the solenoid box is separate or part of a whole "programmer".....
Tech II is offline   Reply With Quote
Old 03-31-2014, 11:13 PM   #7
Junior Member
Thread Starter
 
Join Date: Mar 2014
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
OwenL is on a distinguished road
Default

By control head you mean the primary controls onthe dash, with temp, airflow and vent controls, correct?

I'm not sure if this helps, but here'* a picture of what I describe as the 'vacuum valve solenoid'. This is taken from under the dash on the passenger side. The black vacuum line passes through the firewall, connects to a violet vacuum line behind the glove box, then runs down and connects to a plastic piece that provides vacuum between the white nozzles. So this part has 4 valves and a 6-prong female plug.
I think the easier thing to do is just to replace the main climate controls (on the dash) and then if the problem is still there, replace the valves. Also, in that box, there'* a circuit board next to the solenoids.

Thanks!
Attached Thumbnails
93 LeSabre Airflow Problems-hq2gd48.jpg  

Last edited by OwenL; 03-31-2014 at 11:16 PM.
OwenL is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
MAF/Mass Airflow Sensor Falcon123 1992-1999 6 09-06-2005 11:40 PM
A/C problem ... Airflow decreases under acceleration JCurtis 1992-1999 15 07-08-2005 11:57 AM
ac airflow Dan2003526 1987-1991 5 03-25-2005 01:13 AM
A/C airflow question tonyg 1992-1999 5 06-15-2004 02:02 PM
Low airflow from dash vents Brian95Blown 1992-1999 3 06-27-2003 02:42 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:35 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.