1996 AC Issues
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
1996 AC Issues
My air conditioning system has always been quirky regarding the buttons. Sometimes they worked as intended and sometimes not. It appears the unit has finally failed for the most part. My AC comes on then stops and then hot air gets pushed through the system as if the heater was supposed to be on. My guess is it is the controller. Can this be replaced as a unit? I have not done a lot of research on this yet but I thought I would get some input first.
Thanks!
Thanks!
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Sounds like you are talking about 2 possible problems.
When the A/C comes on does it blow cold?
Do the LEDs follow the pushing of the buttons. Sounds like they don’t? Usually the button contacts have to be cleaned out which is a commonly done.
As for you A/C blowing hot air, you first have to find out if the compressor is running at this time and the fat pipes to the evaporator are ice cold.
If the compressor is cutting out and not running that could be one problem. But if the blend door is in the wrong position, that can be another problem and need to go in the right directing using the right symptom.
When the A/C comes on does it blow cold?
Do the LEDs follow the pushing of the buttons. Sounds like they don’t? Usually the button contacts have to be cleaned out which is a commonly done.
As for you A/C blowing hot air, you first have to find out if the compressor is running at this time and the fat pipes to the evaporator are ice cold.
If the compressor is cutting out and not running that could be one problem. But if the blend door is in the wrong position, that can be another problem and need to go in the right directing using the right symptom.
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
Sounds like you are talking about 2 possible problems.
When the A/C comes on does it blow cold?
Do the LEDs follow the pushing of the buttons. Sounds like they don’t? Usually the button contacts have to be cleaned out which is a commonly done.
As for you A/C blowing hot air, you first have to find out if the compressor is running at this time and the fat pipes to the evaporator are ice cold.
If the compressor is cutting out and not running that could be one problem. But if the blend door is in the wrong position, that can be another problem and need to go in the right directing using the right symptom.
When the A/C comes on does it blow cold?
Do the LEDs follow the pushing of the buttons. Sounds like they don’t? Usually the button contacts have to be cleaned out which is a commonly done.
As for you A/C blowing hot air, you first have to find out if the compressor is running at this time and the fat pipes to the evaporator are ice cold.
If the compressor is cutting out and not running that could be one problem. But if the blend door is in the wrong position, that can be another problem and need to go in the right directing using the right symptom.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
[QUOTE=KJL;1594927606] My guess is it is the controller. Can this be replaced as a unit? I have not done a lot of research on this yet but I thought I would get some input first.
QUOTE]
Not sure on the price, but yes, you can swap the unit. Should take you 30 minutes from start to finish.
http://www.ebay.com/itm/94-95-96-COR...VX~Wvu&vxp=mtr
QUOTE]
Not sure on the price, but yes, you can swap the unit. Should take you 30 minutes from start to finish.
http://www.ebay.com/itm/94-95-96-COR...VX~Wvu&vxp=mtr
Last edited by billschroeder5842; Jul 9, 2017 at 03:17 PM.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
The compressor is running and not short cycling. The pipes are very cold measuring in the high 20s to low 30s. The compressor is getting the 12 vdc signal to engage but when I raise the temp setpoint to 90, it doesn't seem to want to disengage. I am sure there is a min run time timer but my biggest issue remains, cold refrigerant going to the evaporator but system is blowing warm air. Sounds like the blend door. Oddly at the same time the AC started to act up the passenger side window decided to stop working.
Some ground rules. When you run the temp up to 90 (Select recycle), you should get heat out of the vents as well as the compressor keeps operating. This is to have heat and dehumidify the air in the winter so moisture does not condense on the windows. This is normal operation.
When the temp is turned to a low number like 60 or 65, it should blow cold air all the time. It should not go hot at any time.
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
I'm a bit confused on the question at this point.
Some ground rules. When you run the temp up to 90 (Select recycle), you should get heat out of the vents as well as the compressor keeps operating. This is to have heat and dehumidify the air in the winter so moisture does not condense on the windows. This is normal operation.
When the temp is turned to a low number like 60 or 65, it should blow cold air all the time. It should not go hot at any time.
Some ground rules. When you run the temp up to 90 (Select recycle), you should get heat out of the vents as well as the compressor keeps operating. This is to have heat and dehumidify the air in the winter so moisture does not condense on the windows. This is normal operation.
When the temp is turned to a low number like 60 or 65, it should blow cold air all the time. It should not go hot at any time.
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
This morning on my way to the airport when in auto set at 60, it cooled for about 2 minutes then just blew warm air. I will perform more checks on the compressor to make sure it is in fact operational when the unit starts blowing warm. PrelimInary check seems to indicate that the problem is with the control unit.
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Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
It Looks like this thread is the right on for my trouble (1995 coupe)
My ac works pretty well, just at first start selector wont goes up with degrees... It goes instead down. If it is 77° On display when I turn key it stays there for about one half hour, as long as coolant is hot...same thing if i'm at 60° or 85°..
After warmed up I can select every temperature i desire and i've any type of problems...
Is this a sympthom of somthing?
My ac works pretty well, just at first start selector wont goes up with degrees... It goes instead down. If it is 77° On display when I turn key it stays there for about one half hour, as long as coolant is hot...same thing if i'm at 60° or 85°..
After warmed up I can select every temperature i desire and i've any type of problems...
Is this a sympthom of somthing?
Last edited by Christi@n; Jul 11, 2017 at 10:26 AM.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
No, you will not get that data on this from the ALDL connector.
The AC control head can give you positioning of the door. This information is in the FSM and the internet.
But I would first look at the blend door and run the temp from 60 to 90 and see if it moves with full 90* deflection. Remove the blower module from the evaporator box, set blower to 1, look in the box with a flashlight at the door and have some one run the temp up and down. Only the key needs to be at the ON position. (AC can also be set to off and temp door will still operate).
The AC control head can give you positioning of the door. This information is in the FSM and the internet.
But I would first look at the blend door and run the temp from 60 to 90 and see if it moves with full 90* deflection. Remove the blower module from the evaporator box, set blower to 1, look in the box with a flashlight at the door and have some one run the temp up and down. Only the key needs to be at the ON position. (AC can also be set to off and temp door will still operate).
Last edited by pcolt94; Jul 13, 2017 at 10:20 PM.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Good video and have not seen this one. Good links to others also.
I don’t think that is the issue at this time for these reasons.
(Based on some assumptions)
- No additional Freon has been added so I do not think it's overcharged
- It takes a while for a evaporator to freeze over, happens slowly and usually at constant high rpm like being on an expressway. OP says 2 minutes and then warm air.
- When a evaporator freezes over air flow is reduced, he has not indicated this.
- If system is overcharged, the whole system has excess pressure and the low side will be so high that the compressor will not be able to pull down the pressure to the 22.5 psi cut off on the cycle switch. Since you will not be able to get under the 22.5, the evaporator temperature will always be elevated above optimum Freon vaporization and should never freeze.
Unfortunately we don’t have any system pressures which would tell a lot of what s going on.
(Based on some assumptions)
- No additional Freon has been added so I do not think it's overcharged
- It takes a while for a evaporator to freeze over, happens slowly and usually at constant high rpm like being on an expressway. OP says 2 minutes and then warm air.
- When a evaporator freezes over air flow is reduced, he has not indicated this.
- If system is overcharged, the whole system has excess pressure and the low side will be so high that the compressor will not be able to pull down the pressure to the 22.5 psi cut off on the cycle switch. Since you will not be able to get under the 22.5, the evaporator temperature will always be elevated above optimum Freon vaporization and should never freeze.
Unfortunately we don’t have any system pressures which would tell a lot of what s going on.
Last edited by pcolt94; Jul 15, 2017 at 04:38 PM.