Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

2002 Trailblazer EXT rear A/C fan does not come on

11K views 25 replies 6 participants last post by  pugs 
#1 ·
I have a 2002 Trailblzer that has sporatic issues with the rear a/c. The control for it is a round knob with R,0,1,2,3.. It stopped coming on when you try to user the knob..then..for some unknown reason comes on when driving down the road. No idea where to start to fix it? Is it the motor or the knob.. Where can I get parts?? Any pointers on replacing??
 
#4 ·
Almost always the speed control module. I think I've read about 100 members with dead modules, and not one rear blower motor failure. Totally dead ones can be the in-line fuse near the motor. The module can even fail in a way that leaves the blower running with the ignition off and the key out, draining the battery.

 
#14 ·
EXT has three rows of seats, longer wheelbase, stiffer springs for the heavier weight, rear doors not nipped out by the wheel well, 8.6" ring gear rear diffs even for the I6, different power steering pump pulley requiring a shorter serpentine belt, and an HVAC system with rear heater cores and AC evaporators, more than doubling the failure rate for the long tubing runs.
 
#17 ·
I tool off the rear interior piece and the metal cover. I see the motor and can generally follow the diagram, but can't find where the control module is. Do I need to take "everything" out to get to it??

For those that have replaced this, How do I get to the control module?>
 
#18 ·
I don't have that system, but it's been reported to be a bear to get to, on the far (outside body wall) side. I think one report was that it helped to tilt the module away from the body by loosening some screws.

If you did it and posted pictures you would be a hero to FUTURE victims of this GM misdesign.
 
#22 ·
the roadie;1123211That isn't enough? Follow the wiring harness to item #5.[/QUOTE said:
Easier said than done.. That wiring harness goes behind the unit to a place I can't reach and it appears to have 2 screws holding it in. I would assume you have to take the entire unit out to replace it, but didn't want to go tearing it out if someone has done it before and could give some pointers.. I don't mind taking pic's of my EXT, but it is a REAL PITA getting to it without major disassembly.
 
#23 ·
Previous posts (I don't have the rear HVAC) have stated that there are mounting bolts for the assembly that can be loosened/removed to allow the top of the unit to be pulled away from the quarter panel allowing a hand with tool to fit back there and remove the module. The hoses underneath will flex to allow the movement without disconnecting.
 
#24 ·
In that case just Dremel out a rectangular access panel from the outside sheet metal. :yes:

Automotive designers should not be allowed to present their designs for management approval without PROVING they can be serviced. How hard would it have been, starting from a CLEAN SHEET of paper on the GMT370 platform, to put the module where it could have been easily serviced?

Pretty much proves my theory that designers were under ORDERS to make a few items unnecessarily difficult to get to, to assure out-year service revenue for the dealers. More difficulty - more billable hours.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top