This 2003 Chevrolet Trailblazer had a loud ticking noise coming from the rear of the vehicle on the passenger side. In the last post I showed how to remove the trim panels and locate the faulty actuator assembly. Please click here to see that part of this repair.
Once the trim panels were removed it was just a matter of feeling the clicking in the actuator.
The thumb latch has to be depressed to release the harness connector.
There are a total of three phillips headed screws that hold the actuator in place.
It took a little bit of wiggling around but the actuator pulls straight up off of the mode door shaft. The old actuator had several part numbers on it; 47210105, 0297707 and AH24102002. If you want to purchase the most up to date replacement actuators please click here.
I manually turned the shaft to make sure the door moved freely.
Notice the shaft has a half round section with a perpendicular tab to one side. There is a matching recess in the actuator assembly.
When voltage testing, I use an angled pick to probe the harness wires individually. I then clip my meters test lead to the pick.
There are various designs and many are useful for this kind of testing.
Now that the actuator has been replaced the system should be recalibrated. The standard Trailblazer or Envoy would need the driver’s side rear seat cushion lifted to access the fuse box. The vehicle is an EXT version and the whole seat flips up to access the interior fuse box.
There are two push pin retainers that have to be removed as shown below.
I had to locate the fuse labeled “HVAC B” on the fuse box legend.
I had to orient the legend to align the picture with the actual fuse box components.
Once I had located the proper fuse I removed it to start the recalibration process.
The key must be off before the fuse is removed.
Leave the fuse out for one minute.
Install the previously removed fuse.
Turn the ignition on for one minute.
Put your hands in your pockets and Do Not Touch Anything while the ignition is on.
Turn the ignition off for at least ten seconds but no more than thirty seconds.
Turn the ignition on and start the engine. Test the actuator for proper function.
Unless the used ones that you got came out of a vehicle with a lot less miles, I would only replace the one that was clicking. Then test the operation of the system before installing all of the covers.
I ordered my new actuator but cant get it on. The shaft on the door does not line up with the recessed position on the new actuator. I have turned the shaft by hand but it does not come close to where it needs to be. Do I send it back or am I doing something wrong?
You have me at a disadvantage. Year, make and model of vehicle? Part number and location of the actuator you are trying to replace?
Sorry! Its a 06 trailblazer EXT, rear air door actuator(604-130)
Hard call to make. My guess would be that it may have had the harness connected before it was mounted and has over traveled. May have been done by someone else, then returned and sold to you. You might want to compare yours to online images of that part number to see if the orientation matches. .
So my next question is, do I have to return this part or is it possible to still mount it? I did some experimenting with my old actuator and was able to open the box by pulling the side tabs out a little. Then I could lift up the gear and turn it to the position I need it to be in, pushed the gear back into place and replaced the cover. If I did this to the new actuator would it work w/out causing any damage?
The only problem with making the adjustment to the new actuator is that if the case gets damaged during disassembly and the actuator ultimately is faulty then you have voided your warranty.
i have the same issue with my 03 trailblazer, i went to a junk yard and found the same truck. i pulled off the back passenger side pannel and found 2 acuators.should i replace both….i took both off the truck but the one that is clicking is the one you are changing on your website?
Hi Aaron,
A clicking noise is indicative of a broken gear tooth inside the actuator itself.
Mine started clacking after I had replaced the battery. I don’t think my actuator is bad as I had it calibrated once already by dealership. But I did follow your recalibration steps and it did not work. Any other suggestions.
Thanks for this! You solved the problem I’ve been having in my Envoy.
— chase