Help with 2002 trailblazer ltz ext a/c

palimagator

Original poster
Member
Jul 23, 2012
4
OK first of all I would like to thank you for having this site up!!!!! As stated I have a 2002 T/B LTZ EXT and my A/C is starting to do some crazy things to say the least :mad::crazy: Well first of all my system is an automatic dual zone system, but my problems are that the drivers side will only blow luke warm to hot air, the passengers side will only blow hot air and the back seat controls will only blow hot air. Defrost and Recirc functions properly when I use them, I have disconnected and removed the passengers side actuator and it will blow A/C fine out of the passenger front side only. So I have all vents off and the passenger side one on with the recirc function so it will stay a tolerable temp, well tolerable for me not my wife and kids and my furry mutt all the way in the back!!! I have tried to recalibrate the actuators manually to no avail and even tried to turn on the ignition, and then simultaneously press the MODE, FRONT DEFROST and REAR DEFROST switches, that just changed my temp reading for a few hours to -39 then went back to displaying 50(friends suggestion and after we did it he said he didnt know what it did). During the winter when the temp falls below 50 the temp will display the proper outside temperature, I need your help as my wife is hounding me to get this fixed now that the hot weather is upon us. If it's the actuators does anybody have the real part numbers for my style so I dont spend an insane amount, I've seen a huge difference in actuator prices. Thanks for the help!!!!!
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
1) Is the AC compressor operating well - is the receiver/dryer frosty or very cold?

2) Does the external temp sensor lie about the outside temp when it's 80-90 degrees? If so, change it - it's CHEAP even at the local dealer. http://gmtnation.com/f23/02-trailblazer-throttle-body-outside-temp-sensor-not-working-3943/ Located just in front of the radiator - up high.

3) Have you seen my ubiquitous pictures of the actuators and part numbers?

4) Looked on Rockauto, Ebay, and Amazon for prices? Where are you seeing huge variations?
 

palimagator

Original poster
Member
Jul 23, 2012
4
Compressor is operating well I guess

yes it does lie about the temp, I bought one awhile back and the temp reading did not change at all after I swapped it should I have done a calibration of the sysem after changing it or I might have got a bad one.

I have seen the pictures and I have used the part numbers, are they good for my year, when I talk to local auto part stores here in Norfolk, VA they say the huge price difference is because it's a dual zone LTZ automatic system blah blah. just concerned that if I buy one online it might not be the correct one does it matter, especially the passenger temp actuator is the hefty price one I have not looked at any of the others.

Well my wife just told me when I was gone to Iraq during the winter that the drivers and all back ones would blow super awesome heat and the front passenger would only blow cold air reguardless of position.

I'm going to go buy one of the A/C refill cans that have a guage on them and see what the charge is just to make sure.

the roadie said:
1) Is the AC compressor operating well - is the receiver/dryer frosty or very cold?

Thanks for everything

2) Does the external temp sensor lie about the outside temp when it's 80-90 degrees? If so, change it - it's CHEAP even at the local dealer. http://gmtnation.com/f23/02-trailblazer-throttle-body-outside-temp-sensor-not-working-3943/ Located just in front of the radiator - up high.

3) Have you seen my ubiquitous pictures of the actuators and part numbers?

4) Looked on Rockauto, Ebay, and Amazon for prices? Where are you seeing huge variations?
 

palimagator

Original poster
Member
Jul 23, 2012
4
OK,

I changed the ambient air temp sensor and did the reset on the temp panel and it displays the correct temp finally, but every autopart place I talk to around here tells me that the 2002 EXT LTZ temp actuator doors are different than the rest of the models. I"m not sure what to think even the evil empire(dealership) told me the same thing. here are pictures of mine
View attachment 22210


palimagator said:
Compressor is operating well I guess

yes it does lie about the temp, I bought one awhile back and the temp reading did not change at all after I swapped it should I have done a calibration of the sysem after changing it or I might have got a bad one.

I have seen the pictures and I have used the part numbers, are they good for my year, when I talk to local auto part stores here in Norfolk, VA they say the huge price difference is because it's a dual zone LTZ automatic system blah blah. just concerned that if I buy one online it might not be the correct one does it matter, especially the passenger temp actuator is the hefty price one I have not looked at any of the others.

Well my wife just told me when I was gone to Iraq during the winter that the drivers and all back ones would blow super awesome heat and the front passenger would only blow cold air reguardless of position.

I'm going to go buy one of the A/C refill cans that have a guage on them and see what the charge is just to make sure.
 

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BRomanJr

Member
Dec 9, 2011
371
palimagator said:
OK,

I changed the ambient air temp sensor and did the reset on the temp panel and it displays the correct temp finally, but every autopart place I talk to around here tells me that the 2002 EXT LTZ temp actuator doors are different than the rest of the models. I"m not sure what to think even the evil empire(dealership) told me the same thing. here are pictures of mine
View attachment 8477


AFAIK, The temp door actuators did not change from 02 to 03-and up, just the Mode Actuator (Dash / Mix / Floor).

You are making progress, now that the outside temp sensor is accurate (that sensor is very important in temp regulation and now that it is accurate it should have improved your system operation), can you set the system for normal/auto and report what results you get.
 

palimagator

Original poster
Member
Jul 23, 2012
4
Now I just went out and bought a blend door actuator Dorman 604-106 because thats what every parts place and evil empire dealership told me to put in, and now the Pasenger Temp Actuator is working like a champ!! :mad::confused: Now all of you guys are a whole lot smarter than me when it comes to cars and these damn blend door actuators, but why is the 2002 different than the rest side? Now the only thing is that the drivers side blows about 5 degrees difference and a little less force than the passenger side, not sure what to think of that. Now to all in the Nation I ask why is the 2002 LTZ EXT VIN: 1GNES16SX######## actuators different???????? Does that mean that all of the actuators are different from the diagram that Roadie has made for everyone(by the way ROADIE thanks for the diagram I would of never of found it if it was not for your post from the other website we wont mention to this one that has helped me sooooooo much:smile::smile::smile::smile::smile::smile:.


[Q UOTE=BRomanJr;86543]AFAIK, The temp door actuators did not change from 02 to 03-and up, just the Mode Actuator (Dash / Mix / Floor).

You are making progress, now that the outside temp sensor is accurate (that sensor is very important in temp regulation and now that it is accurate it should have improved your system operation), can you set the system for normal/auto and report what results you get.[/QUOTE]
 

BRomanJr

Member
Dec 9, 2011
371
palimagator said:
Now I just went out and bought a blend door actuator Dorman 604-106 because thats what every parts place and evil empire dealership told me to put in, and now the Pasenger Temp Actuator is working like a champ!! :mad::confused: Now all of you guys are a whole lot smarter than me when it comes to cars and these damn blend door actuators, but why is the 2002 different than the rest side? Now the only thing is that the drivers side blows about 5 degrees difference and a little less force than the passenger side, not sure what to think of that. Now to all in the Nation I ask why is the 2002 LTZ EXT VIN: 1GNES16SX######## actuators different???????? Does that mean that all of the actuators are different from the diagram that Roadie has made for everyone(by the way ROADIE thanks for the diagram I would of never of found it if it was not for your post from the other website we wont mention to this one that has helped me sooooooo much:smile::smile::smile::smile::smile::smile:.


BRomanJr said:
AFAIK, The temp door actuators did not change from 02 to 03-and up, just the Mode Actuator (Dash / Mix / Floor).

You are making progress, now that the outside temp sensor is accurate (that sensor is very important in temp regulation and now that it is accurate it should have improved your system operation), can you set the system for normal/auto and report what results you get.


To clarify what I said above, the HVAC actuators in the front of your truck are the same as a Short wheel base that year. The blend door actuator is the only actuator that changed from 02 to 03. The temp door actuators (driver and passenger) are the same as later years. The other (2) actuators (defrost door and recirc door) also did not change.

I don't see why anyone would tell you those parts are more expensive for your truck :confused:. They even use the same actuators between Manual and Automatic HVAC, only the Fan Resistor/Controller in the front changes but not because of EXT.

The rear HVAC system that you have in the EXT has a connected but separate system module in the right rear, and all of its' parts don't change between years or Manual/Auto systems.

What part of the system is not 100% ?? The temp side to side?
Use the system for a while and see if it works properly through all of the climate changes. If it still seems warmer on the drivers side, then have the freon level checked, it may be very slightly low. Worst case you have a leak, on EXTs of that age it is normally in the freon lines going to the rear.
 

AV8ER

Member
Apr 19, 2012
260
I know I have a freon leak on my ext which causes a difference in temps. Is there any particular place to look for the leak on rear ac as stated?
 

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