Rear A/C not working

TONEY BRADLEY

MEMBER
2004 CHEVROLET TRAILBLAZER
5 CYL
2WD
AUTOMATIC
245,000 MILES

Since purchasing this vehicle only the front A/C has worked. I removed the right rear panel and noticed the hot/cold actuator was missing as the actuator door gear was broken. I installed a new actuator door and also purchased two new actuators. (Btw, they don't line up. Can you tell me how to adjust them so I can install them?) Back to my other problem, the front controls nor the rear controls will turn the rear unit on, but I can remove the fuse and reinstall and the blower will come on but only for around 60-70 seconds then shut off. Any help I'd really appreciate it.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,300 POSTS

Welcome to 2CarPros.

If it works for a short time when you remove the fuse, check to make sure the connectors are clean and not corroded. Also, make sure the pins that the fuse pushes into are not loose or pushed inward.

As far as the actuator for the rear, here are the directions specific to your vehicle for replacement:

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The attached pictures will correlate with the directions.

2004 Chevy Truck TrailBlazer 2WD L6-4.2L VIN S
Air Temperature Actuator Replacement - Auxiliary
Vehicle Heating and Air Conditioning Air Door Actuator / Motor Service and Repair Procedures HVAC System - Automatic Air Temperature Actuator Replacement - Auxiliary
AIR TEMPERATURE ACTUATOR REPLACEMENT - AUXILIARY
AIR TEMPERATURE ACTUATOR REPLACEMENT - AUXILIARY

REMOVAL PROCEDURE
1. Remove the right rear quarter trim panel.
2. Disconnect the electrical connector from the air temperature actuator.
3. Remove the retaining screws from the air temperature actuator.

Pic 1

4. Remove the air temperature actuator (1) from the rear HVAC module.

INSTALLATION PROCEDURE

pic 2

1. Install the air temperature actuator (2) to the rear HVAC module.
2. Install the screws to the actuator.

NOTE: Refer to Fastener Notice in Service Precautions.
See: Heating and Air Conditioning > Vehicle Damage Warnings > Fastener Notice

Tighten
Tighten the screws to 1.9 N.M (17 lb in).

3. Connect the electrical connector to the air temperature actuator.
4. Recalibrate the air temperature actuator, See: Vehicle > Programming and Relearning > Re-Calibrating Actuators
5. Install the right rear quarter trim panel.

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Alternate Method (w/o Scan Tool)

1. Clear all DTCs.
2. Place the ignition switch to the OFF position.
3. Install the auxiliary HVAC actuator.
4. Connect all previously disconnected components.
5. Remove the HVAC B fuse for a minimum of 10 seconds.
6. Install the HVAC B fuse.
7. Place the ignition switch in the RUN position.
8. Wait 40 seconds for the auxiliary HVAC control module to self-calibrate.
9. Verify that no DTCs have set as current DTCs.

_______________________

Let me know if that helps.

Take care,
Joe

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