No defrost New actuator but still not working

I assuming the blower motor is working ? Because you don't say one way or the other . When switching from floor to vent to defrost do you hear any noise from in back of the I/P ? Mode door actuator . When moving from heat to A/C does anything change ? Or stay the same ,little air flow ?

I know must people do not want to hear this but you should take it to the dealer an have it checked for DTC'S - diagnostic trouble codes ! The auto parts stores con not read these codes .
More then likely one of the system actuators ( electric motor ) is bad an code is present .
DTC B0229, B0414, B0424, B3761, or B3770
The following DTCs are for the HVAC door actuators:
• B0229 is for the recirculation actuator.
• B0414 is for the left air temperature actuator.
• B0424 is for the right air temperature actuator.
• B3761 is for the defrost actuator.
• B3770 is for the mode actuator.

DTC B0248, B0263, B0268, B0408, or B0418

The following DTCs are for the HVAC door actuators:
• B0248 is for the defrost actuator.
• B0263 is for the mode actuator.
• B0268 is for the recirculation actuator.
• B0408 is for the left air temperature actuator.
• B0418 is for the right air temperature actuator.

There are no vacuum lines for the HVAC , electroniclly controlled .

Mode Actuator
The mode actuator is an electronic stepper motor with feedback potentiometers. The HVAC control module sends signals to the mode door actuator through the mode door control circuit. Zero volts drives the actuator in one direction while 5-volts moves the actuator in the opposite direction. When the actuator receives 2.5 volts, the actuator rotation stops. A 5-volt reference signal is sent out over the 5-volt reference circuit to the mode actuator. When you select a desired mode setting, logic determines the value of the mode actuator signals. The HVAC control module's software uses this reference voltage in order to determine the position of the mode actuator through the mode door position signal circuit. The motor moves the mode door to the desired position.

Defrost Actuator
The defrost actuator operates the same as the mode actuator. The HVAC control module sends signals to the mode door actuator through the defrost door control circuit. Zero volts drives the actuator in one direction while 5-volts moves the actuator in the opposite direction. When the actuator receives 2.5 volts, the actuator rotation stops. A 5-volt reference signal is sent out over the 5-volt reference circuit to the defrost actuator. When you select a defrost setting, logic determines the value of the defrost actuator signals. The HVAC control module's software uses this reference voltage in order to determine the position of the mode actuator through the defrost door position signal circuit. The motor moves the defrost door to the desired position.

Right side or left ? Electronic Automatic Temperature Control or manual ? Temperature or mode door ?
Temperature Blend Door Actuator - LH Removal and Installation
NOTE: It is not required to install the new LH temperature blend door linkage parts included in the LH temperature blend door actuator service part kit if only the temperature blend door actuator requires replacement and the linkage parts are not broken or binding.
LH temperature blend door actuator and linkage

1. Remove the 2 lower steering column opening cover bolts.

1. Detach the lower steering column opening cover.

1. Disconnect the in-vehicle temperature sensor aspirator hose and electrical connector.

1. Position the instrument panel wire harness away from the LH temperature blend door actuator.

1. Remove the 3 LH temperature blend door actuator screws.

1. Disconnect the LH temperature blend door actuator electrical connector.

1. Remove the LH temperature blend door actuator.

1. Manually operate, and inspect the LH temperature blend door linkage for incorrect placement, binding or damage.

Temperature Blend Door Actuator - RH, Dual-Zone EATC Removal and Installation
NOTE: It is not required to install the new RH temperature blend door linkage parts included in the RH temperature blend door actuator service part kit if only the temperature blend door actuator requires replacement and the linkage parts are not broken or binding.
RH temperature blend door actuator and linkage

1. Disconnect the glove compartment damper from the glove compartment.

1. Remove the glove compartment.

1. Remove the RH lower instrument panel insulator.

1. Remove the RH lower floor console trim panel.

1. Remove the 3 RH temperature blend door actuator screws.

1. Disconnect the RH temperature blend door actuator electrical connector.

1. Remove the RH temperature blend door actuator.

1. Manually operate, and inspect the RH temperature blend door linkage for incorrect placement, binding or damage.
2. Mode Door Actuator - Defrost/Panel/Floor Door
3. Removal and Installation
   NOTE: The defrost/panel/floor mode door actuator can be accessed from below the driver side of the instrument panel.
   NOTE: It is not required to install the new defrost/panel/floor mode door linkage parts included in the defrost/panel/floor mode door actuator service part kit if only the mode door actuator requires replacement and the linkage parts are not broken or binding.
   Mode door actuator and linkage
   1. Remove the 3 defrost/panel/floor mode door actuator screws.
   1. Disconnect the defrost/panel/floor mode door actuator electrical connector.
   1. Remove the defrost/panel/floor mode door actuator.
   1. Manually operate, and inspect the defrost/panel/floor mode door linkage for incorrect placement or damage.
   Mode door actuator linkage only
   
   1. Remove the mode door linkage.
      1. Depress the tab and remove the panel door lever.
      1. Remove the floor/defrost door intermediate lever screw and floor/defrost door intermediate lever.
      1. Pull straight outward to remove the floor/defrost door lever.
   Mode door actuator and linkage
   
   1. NOTE: When installing the mode door actuator, make sure that the panel door lever and floor/defrost intermediate lever are correctly aligned with the mode door actuator cam.
      To install, reverse the removal procedure.

I'd have to check actuator movement for defrost. The actuator is electric according to my database. The actuator should be under dash at end of hvac housing.

Isn't air supposed to blow out of the defrost vents ? Otherwise, how is it supposed to defrost a window if it isn't turned on defrost. Does it blow air out when not on defrost ?

Not sure what year, make or model vehicle is in question, but the issue is due to an actuator that has gone bad. Sometimes referred to as a mode actuator or blend door actuator. This actuator controls where air/heat will blow from (defroster vent, forward vents, floor vents or combo, etc.). Good luck. Ron @ Speed-O-Repair.

the door actuator rod may be off or actuator bad.or vacuum line off

Checked the codes and sure enough there was a code B0263 stored in the HVAC module. Your scan tool has to be able to go into the body systems to see this information. A plain OBD2 scanner just won't do the job. This repair is so common that you can diagnose it by symptom if you have to. The most common symptom of course is lack of control over the vent output position and normally it will be stuck in the defroster only position. If it is not currently stuck in the defroster position but you are changing the actuator anyways. make sure that you set the vent position to defrost before starting this procedure. You will see why later.

The data lines show an actual mode door position and a commanded mode door position. They do not even come close to matching.






I laid a fender cover on the dirty floor and set the parking brake pedal. The pedal hits me in the shoulder and prevents me from being able to maneuver around.

Ready to get in there and work.

Start by removing the push pin that holds the driver's floor vent extension in place.

With the push pin released the duct extensions pulls easily from the stationary duct.

The lower screw for the actuator is just above the duct work and cannot be seen. It has to be felt. 5.5 mm head

The second screw can be easily seen as it is at the upper edge of the actuator. Note that it also holds the wiring harness in place.
Developed a slightly different twist to this repair procedure. Could not take good enough pictures from under the dash so hopefully I can show you how on the bench and you can transfer that knowledge to the vehicle.
With the two mounting screws removed and the wiring disconnected, use your fingers and thumb as leverage to push the cam/cog from the actuator shaft. The goal is to leave the cam/cog in place on the end of the heater-a/c case and to remove the actuator motor only.
The old assembly on the left and the new one on the right and The old assembly separated.

Taking the new actuator motor and installing it on the old cam/cog. Remember these steps will be done under the dash. Except for removing the new actuator motor from the new cam/cog, that can be done anywhere. I am just doing this on a bench to give you a clearer idea of what has to be done.



The old cam/cog with the new actuator motor installed. Note the positions of the cam/cog in relation to the motor. Assuming that your actuator has failed in the most common position, blowing out of the defroster vents only, you should not have to do anything other than installing the actuator motor. No indexing of the door shafts to the cam/cog or recalibration of the actuator motors. This is a big time saver.



If the vehicle was stuck in defrost but the new actuator was in different position ( I would say centered ). How do you adjust?
Answer: If you are using the old gear/cog and a new actuator, you should only have to hold the original part in place and install the new actuator. It can only be installed in one of two positions. One will be close and the other will be far out of range. Once the new actuator is installed on the original gear/cog that was held in place, continue to hold the assembly in towards the heater-a/c case and rotate it around until the mounting holes line up. Then perform a recalibration and all should be well.

your blend door actuator needs to be replaced. the default setting for the ac system is defrost for safety reasons. the actuator is not working so it stays in the default setting. most times the whole dash needs to be pulled for this motor/actuator to be replaced

The blend door actuated by solenoids may not be working correctly causing a/c cool air to come out of the windshield vents, rather than the regular front vents.

Defroster Valve Actuator 1996 – 1999 1996 – 1999 HVAC Actuators

To Remove:

1. Remove the air distributor assembly.
2. Unclip the defroster valve actuator from the air inlet.
3. Disconnect the defroster valve actuator from the valve.

To Install:

1. Disconnect the defroster valve actuator from the valve.
2. Clip the defroster valve actuator from the air inlet.
3. Install the air distributor assembly.

Heater/Bi-Level Actuator 1996 – 1999 1996 – 1999 HVAC Actuators

To Remove:

1. Remove the air distributor assembly.
2. Remove the clip and the screws that fasten the 2 halves of the air distributor assembly and separate the air distributor assembly.
3. Unclip and disconnect the heater/bi-level actuator from the valve.

To Install:

1. Connect and clip the heater/bi-level actuator to the valve.
2. Fasten the 2 halves of the air distributor assembly together and torque the fasteners to 13 in-lbs (1.5 Nm).
3. Install the air distributor assembly.

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Removal & Installation Recirculation Actuator 1996 – 1999 1996 – 1999 HVAC Actuators

To Remove:

1. Remove the left sound insulator panel.
2. Disconnect the vacuum hose from the recirculation actuator.
3. Remove the recirculation actuator from the valve.

To Install:

1. Connect the recirculation actuator to the valve.
2. Clip the recirculation actuator to the air inlet.
3. Connect the vacuum hose to the recirculation actuator.
4. Install the left sound insulator panel.