2003 Trailblazer HVAC Schematic

[firemancyr]

I've got a 2003 TB EXT with the typical actuator clicking/non-functioning problems in the rear. I've removed the rear panel to access the actuators, and remembered an old site that had the hvac schematic and part numbers for this truck. I went to that "old" site, and saw that there were issues and our beloved Roadie had moved over here. I was wondering if I could get him or one of you other wonderful tech-heads to repost that schematic so that I can find the part numbers? (The truck now is in the shop to replace the motor mounts, or I'd get them directly off the parts themselves, maybe).

BTW, it's both rear actuators.

 

[Blckshdw]

Here are the part numbers Actuators are the same, hope this helps.

GM: 88892975
AC Delco: 15-72811

 

[George]

here's a parts sheet
2003 Chevy Trailblazer Ext 4WD - TS0912501 Auxiliary A/C Evaporator

 

[The_Roadie]

I suppose you're looking for THIS image, the original:

And not THIS image, which is what I left in the URL that the OS was pointing to.

Glad you followed the bread crumb trail over here.

 

[firemancyr]

That'd be it! lol. Thank you folks so much. Now if only we could get google to direct folks over here moreso than "that other site"

 

[FunkZ]

My 02 EXT started clicking at right rear. The rear HVAC control module was previously replaced with a used part. Did the HVAC B fuse reset, then turned key on and listened. I hear actuators going through their test motions, both front and rear. There's no clicking anymore, but it seems there is no actuator noise when adjusting either the rear temperature or the airflow controls. The blower still works fine.

So is the control module failed again? Or is it the actuator? Looking at the diagram, the 88892975 part is used for the temp and airflow, is there one part for both or would I need two of these?

 

[The_Roadie]

There are two actuators. The designer was just smart and used the same part number in each location. To tell FOR SURE if you have a control module, wiring, or actuator problem will require a voltmeter and a bit of electrical troubleshooting experience. Otherwise it's just shotgunning and that can cost you more. Which was do you want to proceed?

 

[FunkZ]

Thanks for the reply! I went back to the other site and found my previous post from 2009 when the rear hvac control panel was replaced, and it seems the symptoms had been the same. (actuators move after a reset but not from the control module) I looked on eBay but can't seem to find any for sale right now. Do you happen to have the GM part # for the rear hvac panel/module? It's the analog system w/o audio control. (3 dials - blower, temp, airflow)

 

[The_Roadie]

Chevrolet Parts, Cadillac Parts, GMC Parts and Buick Parts powered by Nalley Buick GMC | Nalley Buick GMC Brunswick should have the part number, or use advanced search on Ebay for "completed listings"

 

[mark'stb]

Any tricks to holding door #36 so #33 actuator can be installed? See post #4 for the picture. It just rotates counterclockwise just enough that I can't align the splines. If I eyeball the alignment, the actuator hits the case before it goes in far enough to engage the splines.

 

[mark'stb]

Figured it out. Drilled a 1/8" hole in the case and bent a piece of coat hanger, stuck it in the hole to hold the door up and the actuator slid tight on,

 

[mrrsm]

Some belated Blend Door Imagery and Positional Part Numbering:

 

[Blckshdw]

Bob, the necroposting...