Problems with HVAC and cold air in the winter - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 10-27-2009, 12:59 PM   #1
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Oct 2009
Location: Minnesota
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
FirebirdStud is on a distinguished road
Exclamation Problems with HVAC and cold air in the winter

Hey all,

So, Ill start at the begining. I have a 98 SLE. I worked in England from August 2008 to August 2009. The car was parked in a shed in MN over the year, with the battery unhooked and on blocks.

When I came back and started driving it this fall, it seemed fine. But the weather was average, not too hot to need AC and not too cold to need heat, so I didn't notice any problems. As it got colder though, I noticed problems.

On startup, the electronic display flashes, indicating a stored trouble code. (I have single electronic climate control, not dual) I tried to shift the air from the defrost to the vents, and to the floor. It wouldn't budge, it was stuck on defrost only. Also, it would only blow cold air, not hot. The Tech 2 said it was the Air Mix door, and so I diagnosed it and the book said it was the HVAC programmer that was ****. I called around, and got a local junkyard one for $50. (The stealership one was $479)

Plugged it in, and wala the vents change now! Its magic. But, the thing still blows cold air on warm startup. I dug further, and pulled out the glovebox to watch the Air mix door arm. Sure as ****, on warm startup it goes all the way to the left, thereby letting in outside cold air. I took a long screwdriver and coaxed it back to the right, and it will stay there, thereby giving me warm air.

I plugged in a tech 2 diagnostic computer from work, and it shows that as I adjust the temp, the air mix door counts change accordingly, which makes me believe that the programmer is commanding it properly, but for some reason the acuator just gets stuck on count 56. (0 counts is full hot, and 256 counts is full cold for those who dont know)

So, can the electric motor in the air mix door actuator go haywire? Why would it not do what is commanded? A new actuator is 60 bucks my cost through the dealership, so I dont want to put this part on it if it wont fix my problem.

I have seen through researching that sometimes the gears crack inside of the actuator, but would that be causing my problem if I can manually push the door closed while it is still atatched to the actuator?

Just looking for experience here, as Im sick of having to use the dcrewdriver everytime I get in the car for heat. I would like it to be fixed right.

The car has 160xxx miles on it.

Please let me know if you need more info or anything too.

THANKS!
Cody
FirebirdStud is offline   Reply With Quote
Old 10-27-2009, 06:41 PM   #2
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

This one has been moving down the list all day, so I am bumping it to the top for some attention.
2kg4u is offline   Reply With Quote
Old 10-27-2009, 06:46 PM   #3
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Best thing to do is watch the air mix lever while changing the temp settings. Does the level hit something? Is it binding. Can you tell if it'* still commanding a move and just sitting there?
Danthurs is offline   Reply With Quote
Old 10-27-2009, 06:59 PM   #4
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Oct 2009
Location: Minnesota
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
FirebirdStud is on a distinguished road
Default

Quote:
Originally Posted by Danthurs View Post
Best thing to do is watch the air mix lever while changing the temp settings. Does the level hit something? Is it binding. Can you tell if it'* still commanding a move and just sitting there?
The lever will start moving on its own. Example: I start the car. The temp is set at 90 degrees f. The lever should stay all the way to the right for the heater core air to flow. It will stay there for 10 seconds, then randomly move to the left. I dont know how to tell if it was comanded to do that... any suggestions?

When I watch the lever move, about half way through the travel, it has a hickup, where it acts like it either hits something internally or maybe it has that broken gear syndrome, then it continues on its path.

I dont know how to tell if the actuator was commanded to move or if the controller is bad and it just starts moving, much like the headlight motors on the Firebirds. Sometimes the motor has the endpoint stripped, so it just keeps going and going, without shutting off.

I hope this makes sense. If it doesn't, let me know what needs clarriffied.

Cheers,
Cody
FirebirdStud is offline   Reply With Quote
Old 10-27-2009, 07:32 PM   #5
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

The movement should be vacuum. Take out the glove box liner and you should see the vacuum lines, small and all different colors. If I remember right, the red hose goes to a vacuum solenoid. I had a GTX here a while back that had heat only. I simply reversed the vacuum lines and he had cool air. Now that it'* getting colder, he will need to switch them again. This write up might help. https://www.gmforum.com/t279092/
Danthurs is offline   Reply With Quote
Old 10-27-2009, 07:47 PM   #6
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Oct 2009
Location: Minnesota
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
FirebirdStud is on a distinguished road
Default

Quote:
Originally Posted by Danthurs View Post
The movement should be vacuum. Take out the glove box liner and you should see the vacuum lines, small and all different colors. If I remember right, the red hose goes to a vacuum solenoid. I had a GTX here a while back that had heat only. I simply reversed the vacuum lines and he had cool air. Now that it'* getting colder, he will need to switch them again. This write up might help. https://www.gmforum.com/t279092/
I looked at the writeup. very nice.

However, the air mix door is an electric actuator. It has a DC motor in it, and the programmer plugs directly into the electric air mix door actuator. It sits on top of the duct, just above the programmer. When I take the glovebox out, I can only barely see it through one of the nickel sized holes in the metal framing...

Make sense?
FirebirdStud is offline   Reply With Quote
Old 10-27-2009, 08:30 PM   #7
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Is this what your looking at?
Attached Thumbnails
Problems with HVAC and cold air in the winter-act-lever.jpg  
Danthurs is offline   Reply With Quote
Old 10-27-2009, 08:34 PM   #8
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Oct 2009
Location: Minnesota
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
FirebirdStud is on a distinguished road
Default

yes sir! That is the electric actuator that is not doing its job on my car and making me cold when I want heat! haha.
FirebirdStud is offline   Reply With Quote
Old 10-27-2009, 08:52 PM   #9
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

From the looks of it, it'* not a serviceable part. Do you need a write up on how to replace it?
Danthurs is offline   Reply With Quote
Old 10-27-2009, 11:21 PM   #10
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Oct 2009
Location: Minnesota
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
FirebirdStud is on a distinguished road
Default

Quote:
Originally Posted by Danthurs View Post
From the looks of it, it'* not a serviceable part. Do you need a write up on how to replace it?
You are right, it is not servicable. You just replace it. But I want to make sure that with the conditions present, that this is the culprit. $60 is a lot of coin to me, and I doubt I can return it if it doesn't fix the problem, ya know? I was just hoping someone may have had this problem and can definately say this is the problem, or it is something else...
FirebirdStud is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Climate control problems- Driver side not cold, passenger cold southernengineerin 2000-2005 4 04-04-2010 08:19 PM
1996 Bonneville SSEI Heater Blows cold Air and Hot air!! gmanjeep 1992-1999 9 04-15-2009 12:57 AM
A/C Problems - Cold then HOT then Cold then Hot!!!!! nick s 1992-1999 13 04-22-2006 11:40 AM
No HOT AIR tons of Cold Air HELP Littlehovey 1992-1999 8 01-15-2004 05:40 PM
Cold start,smokey exhaust, and cold air only jeff 1992-1999 0 11-20-2003 02:56 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 11:26 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.