NO AIR COMING THROUGH VENTS

Tiny
KINGDOMBUILDER
  • MEMBER
I have a 94 Deville with the same basic problem. Turn on the AC and air comes through the AC vents then it cycles to the Defrost vents for several minutes then it cycles back to the AC vents. Is this a vacuum or an electro-mechanical problem? Either way does anyone know what to do to correct this before it sticks all the time in the Defrost Mode?
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
KINGDOMBUILDER
  • MEMBER
Hi cadieman,

I don't know I haven't tried the emerg. Brake lately but will do so tomorrow. I have checked & replaced some of the vacuum tubing under the hood as some was cracked. In the process I noticed I had a air value with three outlet/inlets in the vacuum tube line with only two being utilized and connected to the tubing. The third air value outlet has a 8" piece of rubber tubing attached to it but it is not attached to anything at the other end. Its just dangling. I have looked but there doesn't appear to be anything that this was attached to. I don't know how this little plastic air value works inside but I don't see how a vacuum line could be maintained with an open outlet but my AC vent cycle does work back and forth of course and it would seem to me that if I did have an open outlet not attached to anything it wouldn't work at all due to constant vacuum loss. Any info you can give I would appreciate.

Thanks.
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
KINGDOMBUILDER
  • MEMBER
The two air valve connections used are horizontal but the third not used with the 8" piece of tubing just dangling and not connected to anything is vertical. Doesn't this unattached outlet mess up the vacuum in the line or not? Like I said my AC works as connected but I wonder why the third open port on the air valve. Is it supposed to be connected to something or should I block it off?
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
CADIEMAN
  • MEMBER
Spray the vacuum sys. And hoses down with carb spray. When u find the leak the eng. Will surge off idle then it returns. When u spray it again it will surge again. This is where the leak is. Does the cruise work?
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
BLESDOOS@GMAIL.COM
  • MEMBER
  • 2001 CADILLAC DEVILLE
  • V8
  • 2WD
  • AUTOMATIC
  • 84,000 MILES
Ac motor works but center vent wont open and is bleeding a bit on defrost, does not feel cold, clicking noise a few moments when switching on then goes away with I am sure is the ac fan, does the fan come with the motorists
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
CADIEMAN
  • MEMBER
The clicking noise is the programer. The vent linkage is off for the vent. U need remove the a/c vent and inspect the linkage, Its behind the glovebox assy. Also drop r/side under dash panel. Its the black box with a arm on it. If u oper. A/c sys. And listen for clicking noise.
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
BLESDOOS@GMAIL.COM
  • MEMBER
Thank you I will check it out, makes sense, is it difficult to remove
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
FACTORYJACK
  • EXPERT
Let's get a little more descriptive. By center vent not opening, is it a physical dash vent deflector problem, where the door won't open the door of a specific port(right, left, right center, or left center? Or is it a control issue, where no airflow comes from the dash vents? That will determine a course of action. This vehicle has no programmer, that is old technology. It does have 4 actuators-1 mode, 1 recirculate, and 2 for the dual zone temp control, that are controlled electrically by a module(IPM or Instrument Panel Module), which is actually the control head. The clicking could be from the blower motor, does it change as fan speed is ramped up? The clicking noise could also be relevant to the fact you have no mode changes. The mode actuator is located on the left(driver) side of the HVAC case, and is up near/above the gas pedal. This mode actuator can be a bit of a challenge to replace, as it has a cam attached to drive 2-3 different arms that are in time, to give you specific modes(defrost, floor, bi-level, and vent). This is just an FYI, in case you choose to remove it. I have included a picture, as well as the mode actuator R&R procedure, as follows.
Mode Actuator Replacement

REMOVAL PROCEDURE

CAUTION: Refer to SIR Handling Caution in Service Precautions.

Remove the IP carrier. Refer to IP Assembly Replacement in Instrument Panel, Gauges, and Console.
IMPORTANT: The temperature door motor does not need to be removed in order to remove the mode actuator motor.
The temperature door motor is removed in the graphic in order to show the fastener locations.

Remove the mode actuator retaining screws (1).
Remove the mode actuator.
Note the position of the door levers to the cam. The mode door levers must be in the same position in order to reassemble the mode actuator to the HVAC case.
INSTALLATION PROCEDURE

Lubricate the pivots on the mode door levers and the channels on the mode motor cam before reassembling.
Align the mode door levers with the cam slots, as noted on disassembly.
Install the mode actuator to the HVAC module
NOTE: Refer to Fastener Notice in Service Precautions.

Install the mode actuator retaining screws (1).
Tighten
Tighten the fasteners to 1.4 N.M (12 lb in).

Install the IP carrier. Refer to IP Assembly Replacement in Instrument Panel, Gauges, and Console.
Recalibrate the actuators. Refer to BCM Programming/RPO Configuration (DIM) or BCM Programming/RPO Configuration (RIM) in Body Control Module System.

It states in the procedure that the I/P carrier(dash) has to be removed, that is not true. It would make the actuator easier to replace, but you would have the difficulty of removing the dash(which is not too difficult, just labor intensive). There may also be a code associated with your problem, in the IPM. Do you know how to read codes through your on-board feature?
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Wednesday, December 7th, 2016 AT 5:25 PM (Merged)
Tiny
JOECADDY
  • MEMBER
  • 1996 CADILLAC DEVILLE
  • 4.6L
  • V8
  • FWD
  • AUTOMATIC
  • 150,000 MILES
When I turn on the ac on my caddy, no air comes out through the vents what so ever. Not even through the defrost our the floor panel. The ac compressor does come on when I turn on the ac, but no air through the vents at all.I check the the blower motor to check if it had power and ground, and it does. What might be the problem? Do I need a new blower?
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
CAR-MAN145
  • EXPERT
Yes if you have power and ground to the blower motor and its not coming on its a bad blower motor and needs to be replaced
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
JOECADDY
  • MEMBER
Thanks. Today I took it out and connected directly to the battery and it didnt spin at all. So im gonna buy a new one when I have a chance. Thanks anyways
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
GENO1952
  • MEMBER
  • 1997 CADILLAC DEVILLE
  • V8
  • FWD
  • 65,000 MILES
My 97 deville doesn't blow cold/hot air out the vents only the defrost in front window. Is this a fuse problem
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
WRENCHER1
  • MEMBER
The mode selection is done through a series of air doors that are operated by

vacuum. When there is either a partial or total loss of vacuum, the system will

default to either defrost or on some vehicles, heat. Acceleration can also have an

effect on the doors for the same reason.

Look under the hood for a small black plastic hose coming through the firewall.

Follow it to the vacuum source looking for any breaks, cracks or leaks. Also follow

any other lines that branch off because they may go to a vacuum reservoir (storage

tank) and a leak there will cause the same problem. Using a vacuum gauge to

determine if you have full vacuum at any given point is the best way to find it. You

can cut into the line anywhere and splice it back together with a piece of vacuum

hose. Find the broken line, you found your problem.
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
LILMIKE122215
  • MEMBER
  • 1989 CADILLAC DEVILLE
  • 4.5L
  • V8
  • FWD
  • AUTOMATIC
  • 149,900 MILES
I put a new ac compressor.
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
MHPAUTOS
  • MEMBER
I need to know what the problem, is please post some details.
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
BRAD HANTLA
  • MEMBER
  • 2000 CADILLAC DEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 68,000 MILES
Actually two questions:

1. The fan comes on and the heater and a/c put out hot and cold, but no air is coming throught the vents on the dashboard. What is the problem.

2. The system shows check electrical system. This has been on for over a year, and there seems to be no problem. Is it just a glitch in the computer?

Thanks for your help.
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)
Tiny
JAMES W.
  • MEMBER
If you have the computer scanned, what ever tripped the "check" light should be logged in memory. Auto Zone will scan it for free as well as most major parts stores. Let me know what you find.
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Thursday, December 27th, 2018 AT 7:46 PM (Merged)

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