Which a/c actuator?

[1999parkave]

99 Park Ave Ultra. On hot day, it blows cold a/c for passenger, driver is very weak. On a cool day with the heat on, the passenger gets heat, driver gets cool.

So i assume there is a vent stuck open that lets outside air into drivers side?

I pulled off an actuator above the pedals. Seems to be the wrong one because when i twist it by hand, it adjusts output between floor and dash. Which actuator will solve my issue? I live in Miami so I don't even need heat or outside vent, I just want to manually set it to a/c and leave it.

 

[BuickGirlFromMars]

Hold off and auto for 3 +seconds and post what codes display

 

[1999parkave]

I couldn't get it to show any codes. Maybe because I have 2 actuators disconnected? I swear i remember doing it last summer and it did show a code.

I checked with my fingers and the drivers side mix is already turned as far as it will go in the cool direction (by hand at least).

Any reccomendations?

 

[BuickGirlFromMars]

I couldn't get it to show any codes. Maybe because I have 2 actuators disconnected? I swear i remember doing it last summer and it did show a code.

I checked with my fingers and the drivers side mix is already turned as far as it will go in the cool direction (by hand at least).

Any reccomendations?

What does it do when you hold those buttons?
Also I gave you the wrong procedure, I googled it really quick, OOPS!
Check for codes by pressing and holding the "OFF","AUTO" and "RECIRC" buttons for 1 second
You should get the trouble codes displayed for 2 seconds each'

gotta hold 3 buttons haha

 

[LARRY70GS]

Don't know if this will help, but these are the actuators for my 98 Riviera,

 

[1999parkave]

Codes: 33, 34, 40

I already have both the actuators near the pedals disconnected and manually adjusted.

 

[BuickGirlFromMars]

is your passenger temp slider in the center, or elsewhere, and do the lights come on when sliding it with the car on or key on and the hvac in anything but off?

Strange you say you have both actuators disconnected but only one code is for a actuator.

Starting with 34

CIRCUIT DESCRIPTION The passenger temperature control assembly receives voltage signals from the HVAC Control Module (HCM). The signal voltage will vary from 5 volts (open circuit) to 0 volts (short circuit). CONDITIONS FOR SETTING THE DTC ^ The ignition is ON. ^ The circuit is open or shorted. ACTION TAKEN WHEN THE DTC SETS Code B1334 is set. CONDITIONS FOR CLEARING THE DTC ^ Using a Scan Tool. ^ A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. ^ HCM battery voltage is interrupted. TEST DESCRIPTION 1. Perform the Body Control Module (BCM) diagnostic system check before continuing with the diagnosis of this DTC. 2. Determines if the passenger temperature control is operating properly. 4. Ensures that the DTC was not set in error.

then code 33

CIRCUIT DESCRIPTION The right heater temperature sensor is a thermistor that controls signal voltage to the HVAC Control Module (HCM). The HCM supplies voltage on circuit 520. When the sensor is cold, the resistance is high and the HCM will sense a high signal voltage at terminal B9, connector C2. When the sensor warms, resistance is reduced and the signal voltage is pulled low through circuit 61. Signal voltage will vary from 5 V (open circuit) to 0 V (short circuit). CONDITIONS FOR SETTING THE DTC ^ The ignition is ON. ^ Circuit open or short. ACTION TAKEN WHEN THE DTC SETS ^ A default value of 128 counts and 24°C (75°F) will be used by the HCM. ^ The default value allows the system to operate. ^ If the air delivery is heater, defog or defrost the air mix two door will cycle between full hot and full cold. CONDITIONS FOR CLEARING THE DTC ^ Using a Scan Tool. ^ A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. ^ HCM battery voltage is interrupted. TEST DESCRIPTION The numbers below refer to the step numbers on the diagnostic table. 1. Perform the Body Control Module (BCM) diagnostic system check before continuing with the diagnosis of this DTC. 3. Ensures that the DTC was not set in error. 4. Determines whether the cause of the malfunction is the sensor or an open/short in a circuit. 9. The Scan Tool checks for proper sensor operation. Clear all the DTCs after the repair procedures are complete.

then code 40

CIRCUIT DESCRIPTION The rear junction block supplies ignition voltage through circuit 141 (BRN). The HCM commands the actuator to move by supplying voltage on the command line circuit 1199 (DK BLU). The command line voltage and motor actions are as follows: ^ 0 volts moves toward full hot. ^ 2.5 volts stops the motor. ^ 5 volts moves toward full cold. The HCM determines the current position by monitoring the voltage on the feedback circuit 733 (LT BLU). A feedback potentiometer supplies a regulated 5 volt signal by the HCM on circuit 705 (GRY), and a ground from the HCM circuit 1791 (YEL). The pot is gear driven inside the actuator. The feedback voltage is a function of the motor position with a high voltage of 4-5 volts indicating full cold door position. A low voltage of less then 1 volt indicates the full hot position. Operation of the air mix door actuator can be evaluated through Scan Tool data. CONDITIONS FOR SETTING THE DTC ^ Ignition is ON. ^ Feedback circuit is open or shorted. ACTION TAKEN WHEN THE DTC SETS ^ A default value of 128 counts will be used by the HCM. ^ This default value results in only two positions of the actuator full hot and full cold being used by the system. CONDITIONS FOR CLEARING THE DTC ^ Using a Scan Tool ^ A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. ^ HCM battery voltage is interrupted. TEST DESCRIPTION The numbers below refer to the step numbers on the diagnostic table. 1. Perform the Body Control Module Diagnostic Symptom Check before continuing with the diagnosis of this DTC. 2. This test allows the Scan Tool to recalibrate the actuator. 11. Determines if the HCM is malfunctioning. 14. Determines if the actuator is operational.

 

[1999parkave]

View attachment 45798View attachment 45799
is your passenger temp slider in the center, or elsewhere, and do the lights come on when sliding it with the car on or key on and the hvac in anything but off?

Strange you say you have both actuators disconnected but only one code is for a actuator.

Starting with 34
View attachment 45800View attachment 45801

CIRCUIT DESCRIPTION The passenger temperature control assembly receives voltage signals from the HVAC Control Module (HCM). The signal voltage will vary from 5 volts (open circuit) to 0 volts (short circuit). CONDITIONS FOR SETTING THE DTC ^ The ignition is ON. ^ The circuit is open or shorted. ACTION TAKEN WHEN THE DTC SETS Code B1334 is set. CONDITIONS FOR CLEARING THE DTC ^ Using a Scan Tool. ^ A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. ^ HCM battery voltage is interrupted. TEST DESCRIPTION 1. Perform the Body Control Module (BCM) diagnostic system check before continuing with the diagnosis of this DTC. 2. Determines if the passenger temperature control is operating properly. 4. Ensures that the DTC was not set in error.

then code 33

View attachment 45802View attachment 45803

CIRCUIT DESCRIPTION The right heater temperature sensor is a thermistor that controls signal voltage to the HVAC Control Module (HCM). The HCM supplies voltage on circuit 520. When the sensor is cold, the resistance is high and the HCM will sense a high signal voltage at terminal B9, connector C2. When the sensor warms, resistance is reduced and the signal voltage is pulled low through circuit 61. Signal voltage will vary from 5 V (open circuit) to 0 V (short circuit). CONDITIONS FOR SETTING THE DTC ^ The ignition is ON. ^ Circuit open or short. ACTION TAKEN WHEN THE DTC SETS ^ A default value of 128 counts and 24°C (75°F) will be used by the HCM. ^ The default value allows the system to operate. ^ If the air delivery is heater, defog or defrost the air mix two door will cycle between full hot and full cold. CONDITIONS FOR CLEARING THE DTC ^ Using a Scan Tool. ^ A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. ^ HCM battery voltage is interrupted. TEST DESCRIPTION The numbers below refer to the step numbers on the diagnostic table. 1. Perform the Body Control Module (BCM) diagnostic system check before continuing with the diagnosis of this DTC. 3. Ensures that the DTC was not set in error. 4. Determines whether the cause of the malfunction is the sensor or an open/short in a circuit. 9. The Scan Tool checks for proper sensor operation. Clear all the DTCs after the repair procedures are complete.

then code 40
View attachment 45804View attachment 45805
View attachment 45806

CIRCUIT DESCRIPTION The rear junction block supplies ignition voltage through circuit 141 (BRN). The HCM commands the actuator to move by supplying voltage on the command line circuit 1199 (DK BLU). The command line voltage and motor actions are as follows: ^ 0 volts moves toward full hot. ^ 2.5 volts stops the motor. ^ 5 volts moves toward full cold. The HCM determines the current position by monitoring the voltage on the feedback circuit 733 (LT BLU). A feedback potentiometer supplies a regulated 5 volt signal by the HCM on circuit 705 (GRY), and a ground from the HCM circuit 1791 (YEL). The pot is gear driven inside the actuator. The feedback voltage is a function of the motor position with a high voltage of 4-5 volts indicating full cold door position. A low voltage of less then 1 volt indicates the full hot position. Operation of the air mix door actuator can be evaluated through Scan Tool data. CONDITIONS FOR SETTING THE DTC ^ Ignition is ON. ^ Feedback circuit is open or shorted. ACTION TAKEN WHEN THE DTC SETS ^ A default value of 128 counts will be used by the HCM. ^ This default value results in only two positions of the actuator full hot and full cold being used by the system. CONDITIONS FOR CLEARING THE DTC ^ Using a Scan Tool ^ A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. ^ HCM battery voltage is interrupted. TEST DESCRIPTION The numbers below refer to the step numbers on the diagnostic table. 1. Perform the Body Control Module Diagnostic Symptom Check before continuing with the diagnosis of this DTC. 2. This test allows the Scan Tool to recalibrate the actuator. 11. Determines if the HCM is malfunctioning. 14. Determines if the actuator is operational.

The lights on the passenger climate control do work. Thanks for the very detailed response. But is there not a way to logically determine the problem? Outside air getting in drivers side during a/c & heat. How many actuators allow outside air in? Or could there be a hole?

 

[BuickGirlFromMars]

The lights on the passenger climate control do work. Thanks for the very detailed response. But is there not a way to logically determine the problem? Outside air getting in drivers side during a/c & heat. How many actuators allow outside air in? Or could there be a

there is only one source of outside air and its controlled by the system, if the vents have massive temp differences , that is what you feel

 

[1999parkave]

there is only one source of outside air and its controlled by the system, if the vents have massive temp differences , that is what you feel

Is there a name for the actuator that controls that vent? If there is only 1 vent, then what is the reason for all the outside air seeming to be directed to the drivers side? Is either the actuator or the vent itself accessable so i can cut off the flow of outside air manually?

 

[BuickGirlFromMars]

 

[BuickGirlFromMars]

 

[BuickGirlFromMars]

ACTUATORS DESCRIPTION
The dual zone (CJ2) system utilizes 1 actuator for the passenger side and 1 for the driver's side.

The single zone (C68) A/C system utilizes 1 air mix valve actuator. This actuator adjusts the temperature for the entire vehicle.

The air mix valve actuators control the outlet air temperature commanded by the heater and A/C programmer.

A reversible DC motor in the actuators operates the air mix valves. The valves determine how much air passes through the heater core for each side of the vehicle. Refer to the following list:
^ When maximum cooling is required, the motors move the valves and block the air flow through the heater core.
^ No heating of the system air occurs.
^ When maximum heating is required, the motors move the valves and force all of the air to flow through the heater core.
^ Maximum heating of the system air occurs.

The driver air mix valve actuator is contained in the heater and A/C programmer. This actuator controls the temperature of the discharge air on the driver side by operating the driver air mix valve. The valve directs air through or around the heater core.

The passenger air mix valve actuator is mounted on the heater and A/C module assembly.

When not operating in dual zone mode, the 2 actuators will operate the mix valves in unison.

The air mix valve actuators contain feedback potentiometers. The feedback potentiometers inform the heater and A/C programmer of air mix valve positions.

 

[1999parkave]

I'm assuming there's no reason I should bother with the passenger mix actuator if my problem is on the drivers side? If theres only 1 actuator for air inflow source, then I still don't understand why all that outside air seems to direct towards the drivers side? But i guess i'll try to get at that air vent actuator and see if manually adjusting it stops the outside air ingress. Unfortunately that seems to be the one actuator that there are no youtube videos for. Thanks for the diagrams, hopefully i can figure it out from those.

 

[BuickGirlFromMars]

I'm assuming there's no reason I should bother with the passenger mix actuator if my problem is on the drivers side? If theres only 1 actuator for air inflow source, then I still don't understand why all that outside air seems to direct towards the drivers side? But i guess i'll try to get at that air vent actuator and see if manually adjusting it stops the outside air ingress. Unfortunately that seems to be the one actuator that there are no youtube videos for. Thanks for the diagrams, hopefully i can figure it out from those.

Im trying to tell you.. your passenger side is getting the systems intended output air, and the driver side is somehow acting opposite of whati t should do.

 

[1999parkave]

Im trying to tell you.. your passenger side is getting the systems intended output air, and the driver side is somehow acting opposite of whati t should do.

But I have already removed the drivers air mix actuator and manually adjusted all the way to cold and that did not fix it. So unless there is some sort of blockage that is not allowing it to shut all the way, then i don't see how the drivers air mix is the problem.

I understand the computer controls these actuators. But if i adjust them all manually, then i should be able to eliminate the problem, unless there is a hole.

 

[BuickGirlFromMars]

But I have already removed the drivers air mix actuator and manually adjusted all the way to cold and that did not fix it. So unless there is some sort of blockage that is not allowing it to shut all the way, then i don't see how the drivers air mix is the problem.

I understand the computer controls these actuators. But if i adjust them all manually, then i should be able to eliminate the problem, unless there is a hole.

did you hook the drivers side one back up or is it without the actuator installed? There shouldnt be a hole, if there is, its leaking to the inside of the cabin not outside the vehicle. And there COULD be a blockage but its noi as likely

 

[1999parkave]

did you hook the drivers side one back up or is it without the actuator installed? There shouldnt be a hole, if there is, its leaking to the inside of the cabin not outside the vehicle. And there COULD be a blockage but its noi as likely

No i did not hook it back up. Like i said originally, i live in miami and i do not need heat. It's a 25 year old car and i barely drive it, but summer is brutal here. I'm just trying to get all the vents set to max a/c manually and leave it.

 

[1999parkave]

I just feel like the fact the one time it was cold enough outside to use heat, that i was getting cool air out the drivers side is the give away that something is stuck open letting outside air in no matter whether heat or a/c is on. And for some reason it seems to be only (or at least overwhelmingly) affecting the drivers side vents.

 

[BuickGirlFromMars]

No i did not hook it back up. Like i said originally, i live in miami and i do not need heat. It's a 25 year old car and i barely drive it, but summer is brutal here. I'm just trying to get all the vents set to max a/c manually and leave it.

I can tell you right now your car isnt going to like that and your temp variation is now because of the fact you have a missing actuator

Put a working actuator in, calibrate them (I think I posted how above earlier in the topic) , and then at that point check for codes and see what the behavior is.