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Vent issues. 1997 Deville


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Tonight was unusually humid and I was trying to defog the windshield. 

No matter what I did it would not defog. Finally I had the temp up to 85 and it cleared. Thats when  I noticed  something weird.

The left side of the defroster was blowing cool air and the right side was blowing heat. So the right side of the windshield was clear but not the left.

Note. Dual zone was off.

I could not try the dash vents because it  is automatic with the system it has. I think I have had the issue before with this car but I never noticed the different temps coming from the vent. Before I go too crazy I figured I would post here to see what others think.

1997 Deville D'elegance

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Rock, did you notice any clicking noises? 

Possibly the drivers temp blend door sticking or motor may be stripped.

The temp doors have to move in sync when temp is selected in defrost.

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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@rockfangd Could be stuck

2010-12-07_195346_9.gif

I would cycle it through a few times and watch/listen to see if the door/actuator is actually moving....

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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Rock no codes?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

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26 minutes ago, OldCadTech said:

@rockfangd Could be stuck

2010-12-07_195346_9.gif

I would cycle it through a few times and watch/listen to see if the door/actuator is actually moving....

What could be stuck?

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Either of them, the door seals stick and the motors can be inop/stuck. Number 7 in the diagram...

The 97 should throw a code for the actuator as @BodybyFisher stated. I have moved the doors by hand and they will start working, but only for a short time usually.

BBF just went through this on an Eldo I believe, he had a Tech2 at the time to assist in the diag if IRC

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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Rock let me think about this.  There is a way to access the needed into via the DIC.  

I am just surprised that the defrost air can be cooled air at all.  

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Well, the 2 actuators control the L and R temperature doors independently.  

I had not given it any thought, that a passenger control would affect the defroster on that side, that seems odd.  It is affecting the air through the vents and floor vents.  I would think the defroster would be temp controlled to be dehumidified but on a separate circuit than the driver and passenger air delivery and that defrost air is delivered constant temp for both sides.  

Any codes?

It is possible that there is an air driven servo that does not set a code?

Pre-1995 - DTC codes OBD1  >>

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I am sorry. I drove the car but completely forgot to check them.

I question the dual zone on the defrost setting and defog. But with the dual zone being off should not make any difference.

I will try to check codes in a little bit

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Ok so this is interesting.
I sat in the car KOEO

I ran through cycles and this is  what I found.

Passenger temp controls work perfect. Actuator goes through full swing and stops properly, both in dual zone and when controlled by the main(dual zone off)

The driver side is another story. The actuator does not do anything til you get up past 76*,  If you go in increments up or down as long as it is over 76* it sounds normal. When you get down to 76 and continue to go down it sounds like something is struggling and it stops moving. All the way from 76-60 nothing happpens.

I could be wrong but I almost think the door is closed at 76 rather than 60, and at 90 the door is only open maybe half way. I hope that made sense. I say this because it is ice cold but doesnt blow heat til you put it around 80*

Of course no codes. Just a long shot but I may try unhooking the battery, reconnecting it, turning the key on and not touching anything for 1 minute.

That is how the older ones used to relearn positions. 

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Well I found something that is very interesting in my 96 FSM.

Here are two photos from my manual.   They are side by side in the manual and are a continuation of eachother

This is the rightmost photo

DSCN9935_zpsetfvq3u8.jpg

This photo is to the left of the above photo

DSCN9936_zpsliurxcuv.jpg

It is very interesting to note that in the second photo, you see there is a valve that controls the passenger defrost and AC.... I did not know that, its called the Passenger/Defrost - AC valve, and I believe that it is vacuum controlled, probably the reason why you didn't get a code. 

It looks to me like you 'may' be having 2 separate problems the drivers actuator and maybe the passenger AC/Defrost actuator? 

There is a way of going into the ACM DIC DATA to 'see' the commanded vs actual figures.   That is what the TECH2 picks up.  Ill look at my manual later to see how you get in there, I think you toggle ACM, then DATA, then you navigate to what you are trying to observe.  The FSM should have that info, Ill look 

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Thank you. It seems to me that the passenger side was working fine. seems to be a actuator problem for the driver side. Electric though not vacuum.

It is what opens and closes the door that controls the temp. By thee picture it looks like the driver air mix valve.

I might add that the 1997+ Deville is different than the 1996. By how much I am not sure. But the 96 column shift did not have dual zone climate.

the 1997+ was factory with it (control on the passenger door)

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My 96 manual covers the deville, Eldo and Seville.

Keep in mind the the actuator only controls the temp, you see those illustrated in the right photo above.  

What is odd, is that you are getting cold air out of the defroster when heat is commanded if I understand your problem correct, so that would lead me to believe that you have a passenger defrost / AC valve problem on the passenger side.

In the morning I will try to determine what you need to look at in the acm dic for commanded vs actual

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What is happening is that the temp on the driver side is not what it is supposed to be. It is acting like the air mix  door is closed til it gets up to 76*, then from there and up it starts to  open. I may try to disconnect the battery for a little while tomorrow in hopes it may reset. If not I may need to try to relearn.

To clarify heat output is normal from the passenger side but cool on the driver side. 

This may have all happened because of the bad power cable issue I had not long ago. The main hot wire to the underhood electrical center was cobbled and burnt causing all power to cut out randomly

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So you dont have any functional problems on the passenger side?

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nope. All on the driver side.

Today was a classic example. I had the AC on. left side at 76 blew ice cold. right side at cold blew ice cold.

At 76 it should be blowing heat rather than cold on the driver side

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Could be a vacuum issue, like a cracked hose, that keeps enough vacuum on the right side for everything to work but doesn't give the left side enough to fully operate some of the vacuum servos.  See if the shiftier throws the emergency brake off when you shift out of Park.

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This appears to be a bad actuator Rock.  You said no clicking, it usually clicks but it seems you hit a wall at 76. 

I am sitting in the apple store right now with my daughters laptop.  

I need to look in the manual, your commanded and actual should show different data and that would mean your actuator is toast.  

Do you have the sash apart, can you.see the actuators?

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Parking brake releases fine.

The car does not sit still long enough to take the dash apart. I am not even sure where the actuator is.

I thank you so much for your time. I much appreciate it

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OK, Rock, try this, you will be going into the ACM diagnostics DATA, I am about 90% sure of this procedure, as with anything else, its easier to DO it than explain it.  As you toggle through the ACM DATA, you should see identifiable info.  You are looking for the UPPER DOOR, that is the drivers door or actuator.   I will double check this tomorrow on my 97.

Run Diagnostics

Get to PCM?

Press LO fan, till ACM comes up

Press HI fan, to select system

If ACM Data, is not displayed, Press LO fan, till ACM Data is displayed

Press HI fan, to enter

Use the LO fan to toggle through the DATA, you are looking for UPPER DOOR “COM” for Commanded

Using the TEMP control, is the door being commanded (COM) to its proper high and low values?

Use the LO fan again, to find UPPER DOOR “ACT” for Actual, at HIGH temp you should see 100% at LOW temp you should see 0%.

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Found this video. Could it be that easy? Looks to be just above the hush panel on the passenger side.

Does not show any programming info though. is in reference to the issue I am having also

 

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No programming necessary.  Just make sure you keep the rod the same length and not let it change its length. 

There are 3 screws use a 1/4" ratchet set I think its 8mm.  

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I can't believe that he uses a 7/32" socket.  He might have a better fit with a 5.5 mm socket.  Other than that, it seems to be a really good video.

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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