Air Conditioning only comes out of the defrost vents - 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 08-03-2005, 07:46 PM   #1
Junior Member
Thread Starter
 
Join Date: Jun 2003
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Palmettokid is on a distinguished road
Default Air Conditioning only comes out of the defrost vents

I'm in the process of recharging my a/c which hasn't worked for almost a year. Put 2 lbs of freon in the system and everthing is looking good but the air only comes out of the defroster vents.

Has anyone had this problem before? Can you point me to another thread where this was solved?

I have a 1996 Boneville SSE

Thanks in advanced.
Palmettokid is offline   Reply With Quote
Old 08-03-2005, 08:21 PM   #2
Senior Member
True Car Nut
 
Join Date: May 2005
Location: _Phoenix, AZ_ _WCBF '05, '06, '07 Survivor_ ____NEBF '07 Remnant___
Posts: 3,448
Thanks: 0
Thanked 0 Times in 0 Posts
Echo SSEI is on a distinguished road
Default

Echo SSEI is offline   Reply With Quote
Old 08-03-2005, 09:05 PM   #3
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Read through the post Echo sent you. If you can't fix it with all the information in that post then it isn't fixable.

Start by looking for a vacuum leak to the tank then from the tank to the firewall then inside. Try and rule out everything before you pull apart the programmer.
BillBoost37 is offline   Reply With Quote
Old 08-03-2005, 10:02 PM   #4
Senior Member
True Car Nut
 
Join Date: May 2005
Location: _Phoenix, AZ_ _WCBF '05, '06, '07 Survivor_ ____NEBF '07 Remnant___
Posts: 3,448
Thanks: 0
Thanked 0 Times in 0 Posts
Echo SSEI is on a distinguished road
Default

If you get to the point where you need to replace the HVAC programmer "connector" with vac lines, I did a write-up that I PMed to nick that explains how to "crack" open the programmer w/o removing so the connector can be dropped, but it was wiped from my "sent items" box. I have asked nick to PM it back to me and I will post it here when I get it!
Echo SSEI is offline   Reply With Quote
Old 08-04-2005, 08:32 AM   #5
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Quote:
Originally Posted by Echo SSEI
If you get to the point where you need to replace the HVAC programmer "connector" with vac lines, I did a write-up that I PMed to nick that explains how to "crack" open the programmer w/o removing so the connector can be dropped, but it was wiped from my "sent items" box. I have asked nick to PM it back to me and I will post it here when I get it!
Bob..this guy is now looking at what? 8-10 pages of thread? It'* good..trust us. Light is at the end of the tunnel but the trip is necessary.
BillBoost37 is offline   Reply With Quote
Old 08-04-2005, 12:37 PM   #6
Senior Member
True Car Nut
 
Join Date: May 2005
Location: _Phoenix, AZ_ _WCBF '05, '06, '07 Survivor_ ____NEBF '07 Remnant___
Posts: 3,448
Thanks: 0
Thanked 0 Times in 0 Posts
Echo SSEI is on a distinguished road
Default

Quote:
Originally Posted by BillBoost37
It'* good..trust us. Light is at the end of the tunnel but the trip is necessary.
So true, Bill, so true! The end result is worth it!

Here is the write-up I sent to nick to "crack" open the programmer box (without removing it or the dashboard!) so the "connector" can be replaced with vacuum lines:

1. Remove passenger side hush panel (below glove box).

2. On the front (facing the seats) of the HVAC programmer cover/box, there is a bolt/screw about half way up the box. Laying on the floorboard on your back, with a flashlight or the footwell light from the hush panel, you can see the screw on the front of the box by looking up between the box and the backside of the dashboard, underneath the glovebox (see the diagram in the other thread if necessary). The glovebox shouldn't need to be out. Mine was anyways because I was trying all sorts of things. I think the screw is a 10mm. I used a boxend wrench and mainly by feel began to loosen it a turn at a time. I didn't want to take it all the way out because getting it back in would be very difficult. I found out that the box will "open up" enough and the connector will come out without the screw completely removed.

3. As the screw is removed, the box can by pried open with the flat blade of a screwdriver. There are two flat tabs on the box, one below the screw and one above (think of it as kind of like a childs plastic lunchbox sitting upright on one end).

4. Each time the screw is backed out, you can "open" the box a little more. The connector also has a couple of tabs on it that you need to "separate". Everytime I loosened the screw I wiggled the connector and eventually, I wiggled it off/out. It resides in a groove/track in the box that is hard to explain. But once your start wiggling, you'll understand where the catch point is.

5. Once the connector is free from the box, you will be cutting each vacuum line from both sides on the connector and reconnecting the two cut lines back together using new larger vaccum line. I actually brought a piece from the female side of one of the lines (the male side from the box does not have any extra length) with me when I bought the connecting line to make sure I got the right size. Autozone did not have vaccum line small enough so I had to go to NAPA. This is actually the most cumbersome and lengthy part of the process. The lines are tough to shove into the replacement vacuum and doing all five lines took about a half hour of wiggling/shoving. Maybe some wd-40 or other silicone lubricant would help.
Echo SSEI is offline   Reply With Quote
Old 08-04-2005, 07:13 PM   #7
Junior Member
Thread Starter
 
Join Date: Jun 2003
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Palmettokid is on a distinguished road
Default

Here is the latest.

I've got freon in the car and am driving it down the road. The A/C is coming out of the defrost and heater vents. Few minutes later I notice it seems to be getting cooler and realize that the A/C is now coming out of the dash vents. However it feels like the fan is only running half speed.

Is this another symtom of the vacuum line problem talked about in the other posts? Tthought I might drive it a couple of days and see what the vent system is doing. Also considered reseting the computer by unplugging the battery.

Could it have healed itself?
Palmettokid is offline   Reply With Quote
Old 08-05-2005, 12:39 PM   #8
Senior Member
True Car Nut
 
Join Date: May 2005
Location: _Phoenix, AZ_ _WCBF '05, '06, '07 Survivor_ ____NEBF '07 Remnant___
Posts: 3,448
Thanks: 0
Thanked 0 Times in 0 Posts
Echo SSEI is on a distinguished road
Default

nick * has the same problem with the minute or so delay for the AC to move to the vents. This is most likely still vacuum. The write-up I sent to nick was so he could replace the HVAC connector with lines. He has done everything else, including replacing the tank, and his "delay for vents" is still too long, so we think it is a pinched/partially collapsed nipple on the HVAC connector. Do not know about fan at half speed. Try doing all the vacuum line checks/repairs first, the fan speed may be related.
Echo SSEI is offline   Reply With Quote
Old 08-05-2005, 12:48 PM   #9
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

On that fan speed. it should be whatever is selected. Sounds like the vents may be starting to work at a point, however I would believe they are not fully engaged. Meaning the airflow is being split three ways and seeming like you are getting less flow.

Your problem sounds like when you start the car there is no vacuum, once you are running long enough you build enough vacuum to partially engage the vents. You need to check the system starting from the tank into the car with a vacuum gauge to find where your possible leak is occurring.
BillBoost37 is offline   Reply With Quote
Old 08-05-2005, 02:41 PM   #10
Junior Member
Thread Starter
 
Join Date: Jun 2003
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Palmettokid is on a distinguished road
Default

I probably need to clarify some things in my last post. I don't think it'* going to really chnage things though. Drove the car some more today and symptoms seem the same.

Here we go.

Start the car up and it defaults to Auto. A/C from defrost, heater floor vents, and rear console vents. If I leave it alone, which is hard to do, it moves to dash vents after about 30 min of constant driving. It'* still sending a/c throguh the defrost, almost none, heater floor vent and and rearconsole vents.

I agree it must be vacumn related. so what kind of vacuum gage am I looking for and wher is the best place to go get one. Also is there something that tells which vents should be working at each mode selection?

Thanks for your interest to date and the level of knowledge from members.
Palmettokid is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
HVAC Programmer issue? AC only blows through defrost vents 6781camaro 1992-1999 11 04-03-2016 08:19 PM
Air only comes out of defrost and foot vents kparrent Pontiac 5 11-08-2010 04:15 PM
Vents switching to defrost on hills or under power brminder 1992-1999 3 07-14-2005 12:39 PM
1992 bonneville air cond problem. Air only comes out from... Jason B 1992-1999 6 07-06-2004 05:03 PM
LOW AIR COMES THROUGH THE VENTS vze3r85p 1992-1999 3 10-15-2002 06:14 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 07:10 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.