AC problems on a 2004 2500hd

[cjordan]

Just bought this truck. The ac, and heat is acting up. From 60-89 it blows cold, and on 90 it blows hot, there is no inbetween. I've done a little reading, and from what I can tell, there is a sensor mounted in the headliner above the drivers seat, that has been known to cause this problem. My problem is... this truck dosnt have the sensor in the headliner. I think they are calling it a ambient inside tempertaure sensor, or something like that. Has anyone else had this problem? Is there another location this sensor could be mounted instead of the headliner? Or is there something else I should be looking for? I called a buddy of mine who has a 2003, and he dosnt have that sensor in the headliner either. This sensor they are talking about looks alot like a little speaker. Thanks for any and all help.

[gmtech4]

should be up there for an auto system,,,,you should scan the HVAC module for codes first ,,,,or do what ya want lol

 

Inside Air Temperature Sensor Replacement

Removal Procedure

1. Remove the left windshield garnish molding. Refer to
   
   Windshield Pillar Garnish Molding Replacement.
2. Remove the left center pillar assist handle. Refer to
   
   Roof Rail Rear Assist Handle Replacement.
3. Remove the left center pillar garnish molding. Refer to
   
   Center Pillar Garnish Molding Replacement.
4. Remove the left sunshade. Refer to
   
   Sunshade Replacement.
5. Gently pull down the headliner.
7. Disconnect the electrical connector from the inside air
   temperature sensor.
8. Partially remove the inside air temperature sensor from the
   headliner.
9. Remove the sensor grille from the inside air temperature
   sensor.
11. Remove the inside air temperature sensor from the
    headliner.

Installation Procedure

1. Install the new sensor grille to the headliner.
3. Install the inside air temperature sensor to the headliner
   and sensor grille.
5. Connect the electrical connector to the inside air
   temperature sensor.
6. Install the left sunshade. Refer to
   
   Center Pillar Garnish Molding Replacement.
7. Install the left center pillar garnish molding. Refer to
   
   Center Pillar Garnish Molding Replacement.
8. Install the left center assist handle. Refer to
   
   Roof Rail Rear Assist Handle Replacement.
9. Install the left windshield garnish molding. Refer to
   
   Windshield Pillar Garnish Molding Replacem

[gmtech4]

[cjordan]

 

should be up there for an auto system,,,,you should scan the HVAC module for codes first ,,,,or do what ya want lol

 

Inside Air Temperature Sensor Replacement

 

 

 

 

 

 

Removal Procedure

1. Remove the left windshield garnish molding. Refer to

    

   Windshield Pillar Garnish Molding Replacement.

2. Remove the left center pillar assist handle. Refer to

    

   Roof Rail Rear Assist Handle Replacement.

3. Remove the left center pillar garnish molding. Refer to

    

   Center Pillar Garnish Molding Replacement.

4. Remove the left sunshade. Refer to

    

   Sunshade Replacement.

5. Gently pull down the headliner.
7. Disconnect the electrical connector from the inside air

   temperature sensor.

8. Partially remove the inside air temperature sensor from the

   headliner.

9. Remove the sensor grille from the inside air temperature

   sensor.

11. Remove the inside air temperature sensor from the

    headliner.

 

Installation Procedure

1. Install the new sensor grille to the headliner.
3. Install the inside air temperature sensor to the headliner

   and sensor grille.

5. Connect the electrical connector to the inside air

   temperature sensor.

6. Install the left sunshade. Refer to

    

   Center Pillar Garnish Molding Replacement.

7. Install the left center pillar garnish molding. Refer to

    

   Center Pillar Garnish Molding Replacement.

8. Install the left center assist handle. Refer to

    

   Roof Rail Rear Assist Handle Replacement.

9. Install the left windshield garnish molding. Refer to

    

   Windshield Pillar Garnish Molding Replacem

I wish it was there Mr.Rob, that would be a cheap easy way to see if that was the problem. I somewhat pulled the headliner down a little bit last night to see if maybe it was there, and the previous owner installed a new headliner, but didnt replace the sensor. I found two wires that went to where it looked like the sensor should be, but there wasnt a hole in the headliner. I could tell one of the wires was orange, but couldnt tell what color the other wire was. I could tell there was a piece of black tape where the wires went to the headliner. Like I said though, there isnt a hole in the headliner where the sensor should be. Did the 03s have this sensor as well? Because my buddies truck dosnt have it either is the only reason Im asking. Thank you for your time and help.

[gmtech4]

03 auto HVAC has this sensor mr jordan lol

 

[ATMINF]

They had a recall on our HVAC system on our trucks, I remember getting a letter in the mail. You might be able to take it to a local dealer and see what they can do.

[gmtech4]

They had a recall on our HVAC system on our trucks, I remember getting a letter in the mail. You might be able to take it to a local dealer and see what they can do.

that was for heater harness and resistor for overheating

[Chris]

Also the recall was fpr manual control systems

[cjordan]

I doubt it, but I have to ask any how. Would it make a difference since this is a 2004.5? I guess I should have said that in the original post. I can not figure out why this truck dosnt have the sensor above the drivers seat.

[Chris]

May havr been removed when the headliner was done

[txab]

http://www.truckmodcentral.com/forums/f63/how-replace-auto-climate-control-aspirator-gmt800-chevrolet-tahoe-1468/

[cjordan]

In those pictures there was an orange wire for the aspirator, so maybe im in luck. I will pull the headliner down today and see if I can tell more about it. It is very possible that they replaced the head liner and didn't reinstall the sensor. Thank you all for your time and help.