Mechanics

NO AIR COMING THROUGH VENTS

1999 Cadillac Deville

Air Conditioning problem
1999 Cadillac Deville V8 Front Wheel Drive Automatic 60500 miles

I recently bought this car, it was missing the AC Comp Fuse Relay so I put a new one in. The problem I am having is when I turn on the AC, heater, or the defroster, no Air comes through the vents. When I turn on the AC I can hear it come on, but no air comes out. Where should I start?
Avatar
KINGNOAH
March 15, 2010.



Start by pressing off and warmer on the climate panel, after the segment check it will display codes. Record the codes. The ones that would relate to your concern will be ACM codes.

Factoryjack
Mar 15, 2010.
It said the following
NO ACM
PCM?
B2711 CURRENT
P0603 HISTORY
B1552 HISTORY
U1255 HISTORY
B1147 HISTORY
B1148 HISTORY
B1327 HISTORY
B1971 HISTORY
B1983 HISTORY
B2473 HISTORY
B2477 HISTORY
B1771 HISTORY
U1000 HISTORY
U1305 HISTORY

Tiny
KINGNOAH
Mar 16, 2010.
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.

Factoryjack
Mar 16, 2010.
Thanx, soon as I do I will let you know whats up

Tiny
KINGNOAH
Mar 17, 2010.
Where is the blower motor relay switch?

Tiny
KINGNOAH
Mar 24, 2010.
There is no blower motor relay switch, it's speed is controlled by the AC programmer, on bus information from the climate panel.

Factoryjack
Mar 25, 2010.
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.

Tiny
KINGNOAH
Mar 26, 2010.
If the car is a 99 deville, there is no blower motor relay. The red wire that you checked for power, is off of the 50A inadvertent fuse in the left underhood 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.

Step
Action
Value(s)
Yes
No

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?
1.0 Ω
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?
250 KΩ
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.

Factoryjack
Mar 26, 2010.
Wow! Thanx Gstacey 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?

Tiny
KINGNOAH
Mar 27, 2010.
When I checked for power at the blower motor, I used the battery.

Tiny
KINGNOAH
Mar 27, 2010.
Page 1 of 3