NO AIR COMING THROUGH VENTS

It sounds like you have a blend door actuator, blower motor going out or a programmer. Lets start by turning the key to the on position without starting the car. Press off and warmer on the climate panel at the same time. It will then display any codes. The ones that would relate to your concern we will be able to fix it.

In stating that you can hear it come on, is it the compressor you are hearing, or is it the blower motor that you are hearing? Simply stated, is there just no airflow out of the dash vents, or out of any vents(floor, dash, or defrost). If it is no airflow at all, check for power and ground at the blower motor connector big wires with a test light across them and engine running. If you have a light, replace the blower motor.

Thanx, soon as I do I will let you know what's up. Where is the blower motor relay switch?

There is no blower motor relay switch, it's speed is controlled by the AC programmer, on bus information from the climate panel.

Here is a diagram and guide to help us do some testing.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check for power at the programmer.

Please let me know

I started this thread because No air at all was blowing through the vents. I checked if power was getting to the blower motor with a test light. There was so I replaced the blower motor. Still the new blower motor will not spin.

Although someone just said that there is no blower motor relay, I just went to autozone and bought one for $16, also the dealership sells one for my exact car for $45.
I can not locate the blower motor relay, can anyone help me?

Also on the computer I am getting this code
ACM : B1312 - High Side Temp Sensor Open Circuit

What exactly does that meen, what does it do, and how do I replace it?

I appreciate all the feedback and all the help.

If the car is a 99 deville, there is a compressor relay. no blower motor relay it is all solid state. The red wire that you checked for power, is off of the 50A inadvertent fuse in the left under hood fuse block. The black wire goes to G204, which is down below the instrument panel left side, behind the kick panel. And the gray wire is speed control from the A/C programmer. When you checked for power at the blower motor, did you also use the blower ground wire, or just an engine or battery ground? I don't know which relay you were sold, but there is no blower relay. If you have power and ground at the blower motor, and can verify continuity of the gray wire to the programmer. I would say you need a programmer. To validate what I have said, and to illustrate no reference to blower relay, here is the factory diagnostic chart for no blower. It is in text form, if I uploaded the illustration it would be too small to read.
Blower Motor Inoperative at Any Speed (Front)
Test Description

Performs the Diagnostic System Check before continuing with the diagnosis.

Verifies the blower operation in both normal and overide modes.

The Scan Tool displays the blower speed input voltage from the Heater and A/C Programmer to the Blower Motor Assembly. Checking for the cause in CKT 754 or the Heater and A/C Programmer output.

Repairs the main speed input to the blower motor. Data Line between the IPC and the Heater and A/C Programmer are suspect.



1 Did you perform the diagnostic system check?
--
Go to Step 2
Go to Diagnostic System Check

2 Turn the key to the ON position.
With the engine running, connect the Scan Tool .
Set the blower on high (99%).
Use the Scan Tool to display the function test for the blower.
Change the blower speed. Observe the change in speed as the numbers decrease.
Did you complete the procedure?
--
Go to Step 3
--

3 Is the blower operation non-existent or intermittent?
--
Go to Step 6
Go to Step 4

4 Does the blower speed consistently decrease at a gradual rate from 99 to approximately 30, and then stop?
--
Go to Step 7
Go to Step 5

5 Is the blower speed consistent, then OFF?
--
Go to Step 8
--

6 Use a Scan Tool to view the blower speed.
Command the blower to the HI speed (100%).
Command the blower to the LO speed (42%).
Does the commanded value equal the actual value?
--
Go to Step 10
Go to Step 9

7 The blower is operating properly.

Inspect for improper temperature control.

Did you inspect for improper temperature control?
--
Go to Step 18
--

8 Exit the diagnostic.
Start the engine.
Select the LO blower.
Inspect the voltage at blower connector B.
Is the voltage greater than the specified value?
9 V
Go to Step 17
Go to Step 13

9 Use the Scan Tool to view the blower speed.
Set the A/C system to 75 degrees AUTO MODE.
Increase or decrease the set temperature.
Is the blower speed (%) within the specified value?
40-100%
Go to Step 10
Go to Step 11

10 Inspect the voltage at the blower motor connector B.

Is the voltage greater than the specified value?
4 V
Go to Step 12
Go to Step 13

11 Replace the heater and A/C programmer. Refer to Programmer Replacement

Is the repair complete?

Go to Step 18

12 Disconnect the blower.
Inspect the resistance of connector C to the battery voltage.
Inspect the resistance of connector A to ground.
Is the resistance greater than the specified value?

Go to Step 14
Go to Step 15

13 Inspect CKT 754.
If CKT 754 is OK, replace the heater and A/C programmer. Refer to Programmer Replacement
Is the repair complete?
--
Go to Step 18
--

14 Inspect the fuse.
Repair CKT 50 or CKT 542 as required.
Is the repair complete?
--
Go to Step 18
--

15 Turn the key OFF.
Inspect the resistance of connector B to ground.
Is the resistance less than the specified value?

Go to Step 13
Go to Step 16

16 Replace the blower motor assembly. Refer to Blower Motor and Fan Replacement

Is the repair complete?
--
Go to Step 18
--

17 Set the blower speed to HI.

Does the voltage change to less than the specified value?
4 V
Go to Step 16
Go to Step 13

18 Using the Scan Tool clear the DTCs and verify the operation.

Did you clear the DTCs and verify the operation?
--
Go to Diagnostic System Check
--

The high side temp sensor is just above the blower connector. Open circuit relates to it being disconnected, faulty sensor, or faulty wiring to the sensor, or a faulty programmer. This was not in your original list of codes you posted, was it possibly disconnected during blower replacement.

Wow! I really appreciate it. Tomorrow morning I will go re-check everything.

when I checked the power going to the Blower motor, I simply used a test light to test the plug. I grounded the test light to a random piece of metal on the car. It lit up on one of the prongs, not sure which one but I figured it was the power.

When checked if the blower motor worked, I hooked it straight to the battery and it spun back n forth. The new one did the same thing.

How would I check the ground? I have been searching for the ground wire and have been unsuccessful in locating it.

I believe I did disconnect the High semp temp sensor, I will reset the Codes and see if it comes up again.

Would it be safe to just replace the ac/heat programmer all together?

When I checked for power at the blower motor, I used the battery.

You can check the blower ground using the battery as well, just connect your test light to positive, and touch the ground wire. If it lights, you have ground. If you have ground, check the gray wire for voltage with a voltmeter when the blower is commanded at full power. check for around 4 volts.

The ground is ok, and the gray wire is ok.

If that is the case, you have power, ground, and a speed output from the programmer, you should have an operable blower motor. When you said you checked the blower, connected it straight to the battery, and it spun back and forth, what did you mean spun back and forth? If you have not mounted the new blower, connect the blower motor connector to it, set it on the engine so the fan is not hitting anything, start the vehicle with the HVAC on to hi fan speed and see what happens. It will take a few minutes, especially if it is stone cold.

it spun back n forth. it spun forward about 2 circles, and back, My original did it, and also the one I bought did the same exact thing, my neighbor hooked up a blower he had (a blower from the 80s). and it spun like a fan, continously in the same direction. I figured the original was fine because it acted the same way the one I bought did.

When I had hooked it straight to the battery, should it spin continously? or should it rock back n forth?

When you had it hooked to the battery, I am not sure if it should have spun at all, with no speed input that would come on the gray wire. For it to spin back and forth, theoritically would mean it is reversing polarity, and that would be an issue with the circuit board in the blower. I would not think a blower from the 80's would connect, as it would be a two wire blower, and speed would be controlled through the blower power module. If you have power on the red wire, ground on the black wire, and a voltage output on the gray wire, you should have blower operation. Looking toward the first posts, when you checked codes, you said no ACM, was that no ACM data? Have you tried clearing all the codes and seeing if any return. Also, have you tried connecting the replacement blower to the blower connector outside the vehicle and checking it's operation, with the engine running.

when i connected it to the battery, I simply took a cord with 2 wires on it, and connected one end to my car battery, and the other end to the blower motor. That is how I was able to test the 80s motor, and that is how I got my original blower motor to spin.

Also, when I tested the new blower, I did not have the car running. All I did was turn the ignition on and set the blower on high (nothing happened).

Have you plugged the replacement in to the vehicle harness, and checked it with the fan selected to high speed, and the engine running? A two wire fan ran to the battery is going to spin at high speed in one direction, you are just powering a motor at this point. I can't explain why the fan spins back and forth when connecting two wires to it, it is not a valid test.

I plugged the replacement into the harness, put the fan on high, but the engine was not on.

If you have power on the red wire, ground on the black, and you say the gray wire is good, you have everything you need to sustain blower operation. If the replacement blower does not work, either it is faulty, or incorrect for the application. There is not much else that can be said, if all wiring is good, then all possibilities of anything other than the blower have been exhausted. The IPc sends speed request via class 2 communications to the programmer, the programmer sends speed outputs to the blower logic, the power and ground run the motor.

Ok, I went and bought a brand new blower motor and it works great!

I got it from Amazon for $240.00 it came with a new speed controller.

https://www.amazon.com/gp/product/B000C9CCBE/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B000C9CCBE&linkId=955e757fddc357bb9fd8e083a611d696

But now there is no cold air. I went and bought a recharge from auto zone and had them do it for me, but still no cold air, and then when I try to blow hot air, no air comes through the vents.

1. When I put the AC on High/Coldest setting, the air comes out room temperature.

2. When i put the AC on High/Hottest setting, I can hear the air blowing but none comes through the vents.

At max heat, the air should come out the floor ducts. If you don't achieve max cooling, is the compressor coming on? If it is coming on, it will need the pressures checked to take the next step. If the compressor is not creating any pressure, or the expansion device(orifice tube) is not creating a pressure differential, you will have no cooling. If the compressor is not coming on, check and clear any ACM, and PCM trouble codes and see if it comes on after that.

It sounds like you have a blend door actuator that is out. Here is a guide and the part so you can get the car fixed.

https://www.2carpros.com/articles/replace-blend-door-motor

The part:

https://www.amazon.com/gp/product/B0012PWSKC/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B0012PWSKC&linkId=66d79ca2683525acab5508b692d09027

Let me know

2000 Cadillac Deville

Hi:
My brother has a 2000 cadillac deville and has a problem with the front AC vents. They seem to be stuck in a closed position and do not let any AC through those vents. The rear vent gets AC and when in defrost mode cool air comes through the defrost vents. He has taken the dash board apart but has not been able to find any access to the vents. He thinks they may be blocked or that something is preventing them from toggling open and closed for some reason. Is there anywhere to obtain a vent or dashboard diagram as to where components are located under the dash. Or if you have any other suggestions for him that would be greatly appreciated. Any help or direction you could give would be great. Hope I explained this well enough...

Denise

u have a vacuum condition. go to l/f fender area and
locate the vacuum canister check for leaks.You may have to replace it.also check the criuse control for proper oper.if u have low vacume it wont oper. properly.check all vacuum sys. for leaks. the emergency brake release also. Check the vacuum at a/c programmer.

Does the system change modes, and try to blow out vents. If it only blows out of one mode(defog/floor), there may be an actuator issue at fault. There is no 'vacume' in this system, the park brake release and cruise are electro-mechanical as well.

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?

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.

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?

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?

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

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.

Thank you I will check it out, makes sense, is it difficult to remove

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?

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 ?

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

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

my 97 deville doesn't blow cold/hot air out the vents only the defrost in front window. is this a fuse problem

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.

i put a new ac compressor.

I need to know what the problem, is please post some details.

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.

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.