2003 Envoy, changed the front and rear mode actuators recently, hardly ever drive the vehicle, go to move it over the weekend and I'm getting clicking big time from the rear and suddenly fron vents are not blowing, both have new actuators, vehicle has been driven less than 100 miles. Is it just cheap parts or something else ? I tried the reset and all that. Getting tired of cheap parts from China.
HVAC mode actuators
- Thread starter splashfun
- Start date
Which brand actuators did you get? Where did you buy them? I think they're all made in China and unless you get the GM parts (they are still available), parts quality is iffy at best.
Did you do the relearn right after replacing them?
Did you do the relearn right after replacing them?
I've also had bad luck with a CCC actuator. About to try another one from Amazon (A-Premium). If that one fails, I'll go to an OEM.
I finally got it, bit of a story but may be helpful to somebody else. When I first put in the new actuator and tried it the vents were working so I figured it was fixed, don't use it very often so did not notice for a month or so that it would not switch to floor or do mix mode. Could also hear a slight clicking noise once in a while which is why I thought maybe new actuator was bad. It's a pain to get to but ended up pulling it out, decided to open the cover and everything looked fine no broken or cracked gears, applied 12 volts to motor and it ran fine. Got looking online and one guy made the comment that when installing the new actuator the gear has to be in the same position as the old one, I had kept the old one and the box for the new actuator so I looked at the old one and that outer gear was in a different location than the new one and I also noticed a note in the box I had missed that said the new actuator was in the mid-position and the door position would need to be adjusted accordingly. There is no way to move the gear by hand without breaking it so about the only way I could see to get it to the same position as old one was to open it up and adjust gears (which created a new problem didn't realize until later) and my vent door is weighted or something (I have a 2003 Envoy XL), when ignition is off the vent door goes to vent position, can not move it to mid-position, won't hold. Back to actuator, I adjusted the gears until that big gear/cam was in the same position as old one, put cover back on and reinstalled it, did not screw it on, just held it with my hand and checked the different mode positions with ignition on, this time all I got was the floor vents. Back to checking online, one post talked about the counter being out of range and so he took a multimeter and measured the resistance between pins 9-10 and 9-7 and set the counter to a midpoint, that is done by turning the counter gear (see photo - counter is blue gear to upper right) until the resistance reading is about equal on 9-10 and 7-9, on mine mid-point was about 4.5k ohms for each side. It's pretty sensitive and you have to hold gears when sliding it back together and aligning that outer gear/cam. I put dots on gears with a felt tip pen when I had counter at mid-range so putting it back together just made sure dots lined up and snapped cover back on. I then attached the connector without installing the actuator and with ignition on hit the different modes and watched the gear/cam move, it worked like it was supposed to. Reinstalled actuator and tried it and all I was getting was air blowing from mid vents, pretty frustrated at this point. Wasn't sure if my scanner could read live data or do the re-cal but it did, I read the data stream and it was getting all the right commands, floor, vents, mixed and defrost. Pulled the actuator again but left it connected and watched it and it was moving like it should. Finally thought to myself its working like it should what could be wrong and it finally dawned on me, is the cam not engaging with the cam on the door, not enough room to see and once the actuator is installed it blocks the view even more, by chance I just happened across a video/blog where one guy was having similar trouble, he said the only way is to pull the cam off the actuator and align it and get it engaged with cam on the door and then push actuator onto cam, that worked for me, you have to be careful and try to hold the cam in place as you push the actuator on but finally got it to work. Long story and frustrating but learned a lot.
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Not sure which vehicle you are working on but this should work for 2003 Envoy on up, Trailblazer may be the same. If you are working on the mode actuator, plug it into the connector without installing it, ignition on engine not running, may need a mirror, press mode button to vent, the outer gear/cam should move, if it doesn't it may be because its at max on one side, press mode button for floor and see if it rotates, if it does rotate press mode button to mixed mode (vent-floor) and see if it moves again, should only go half way between, if it moves then push mode button to vent and it should move again, if it moves to 3 spots you are in good shape, sequence it through a couple of times to see if its consistent, then press mode button for mixed mode, on other side of actuator there are 3 lines/marks, it should be lined up on middle mark, if it is, work the outer cam/gear off the shaft and put it in first making sure teeth are engaged with door gear, if you look at the photo you will notice a little slot on the outer edge of the cam, if you feel along the edge of the door gear it has a little raised piece, the slot on the cam aligns with that, once its aligned and teeth are engaged, make sure the center of cam is on center of door assembly, best you can keep all that in place and push actuator post onto the cam, should work from there if cam stayed aligned and engaged. Now if when you pushed mode buttons and cam did not rotate you are going to need to open up actuator and adjust the counter gear (you will have to pull the med size white gear out and tilt the inner cam gear (big white one) so you can turn the blue counter gear until you get ohm readings on pins 9-10 and 7-9 that are approx equal, once you have done that carefully insert and engage all gears without letting counter gear move (a tiny bit of movement may happen) and making sure its at middle mark on backside of actuator, snap it back together and see if it moves with changes on mode button.
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...and they are here as Plain Text:
Response: Here is the organized, step-by-step list of important elements to fix a faulty mode actuator on a 2003 Envoy XL (and possibly other similar vehicles):
**Step 1: Initial Troubleshooting**
* Check if the new actuator was installed correctly and the gear/cam was in the same position as the old one
* Verify that the counter gear is not out of range by measuring resistance between pins 9-10, 7-9 (should be approximately equal at around 4.5k ohms)
**Step 2: Adjusting the Counter Gear**
* If necessary, open up the actuator and adjust the counter gear to get an approximate midpoint reading on the multi-meter
* Use a felt-tip pen to mark the gears with dots for alignment
**Step 3: Testing the Actuator without Installation**
* Plug in the connector without installing the actuator
* Turn the ignition on, press mode buttons (vent, floor, mixed) and observe if the gear/cam moves correctly
+ If it doesn't move or only moves to one position, try adjusting the counter gear
**Step 4: Adjusting the Cam**
* Remove the cam from the actuator shaft
* Align the slot on the cam with a raised piece on the door gear (using a mirror may be necessary)
* Engage the teeth of the cam and door gear
* Ensure the center of the cam is aligned with the center of the door assembly
**Step 5: Reinstalling the Actuator**
* Carefully push the actuator post onto the cam, ensuring it stays engaged
* Test the mode buttons to ensure proper function (vent, floor, mixed)
If these steps don't resolve the issue, further troubleshooting may be necessary...
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...and they are here as Plain Text:
Response: Here is the organized, step-by-step list of important elements to fix a faulty mode actuator on a 2003 Envoy XL (and possibly other similar vehicles):
**Step 1: Initial Troubleshooting**
* Check if the new actuator was installed correctly and the gear/cam was in the same position as the old one
* Verify that the counter gear is not out of range by measuring resistance between pins 9-10, 7-9 (should be approximately equal at around 4.5k ohms)
**Step 2: Adjusting the Counter Gear**
* If necessary, open up the actuator and adjust the counter gear to get an approximate midpoint reading on the multi-meter
* Use a felt-tip pen to mark the gears with dots for alignment
**Step 3: Testing the Actuator without Installation**
* Plug in the connector without installing the actuator
* Turn the ignition on, press mode buttons (vent, floor, mixed) and observe if the gear/cam moves correctly
+ If it doesn't move or only moves to one position, try adjusting the counter gear
**Step 4: Adjusting the Cam**
* Remove the cam from the actuator shaft
* Align the slot on the cam with a raised piece on the door gear (using a mirror may be necessary)
* Engage the teeth of the cam and door gear
* Ensure the center of the cam is aligned with the center of the door assembly
**Step 5: Reinstalling the Actuator**
* Carefully push the actuator post onto the cam, ensuring it stays engaged
* Test the mode buttons to ensure proper function (vent, floor, mixed)
If these steps don't resolve the issue, further troubleshooting may be necessary...
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spfautsch
Member
Though I initially came here searching for another problem, I noticed this and it's ironic.
The irony being my rear mode actuator ('06 Envoy XL) had been working perfectly since April 30th of this year. When I first acquired the vehicle back in fall of 2023 both the rear actuators reduction gears were little more than crumbs of plastic. Replaced both with AC-Delco / "GM GENUINE 1572811" from RA. Then in April I was again confronted with the "tick of death" sound from the rear. Replaced under warranty. Yesterday I had it parked outside for several hours and when I moved it back in the garage was once again confronted with the "tick of death".
My gut tells me these parts are just CCC (actually made in Korea so CKC).
I have a whole pile (4 to be exact) in my parts bin. One Dorman from the other LWB we own that wouldn't calibrate out of the box and three that look like GM OE parts with 'Made In Korea' molded into the cover above the barcode. Of all of these, the first one I opened had copious amounts of grease on the potentiometer portion of the PCB. I think I'm going to try cleaning this off and attempt to make one out of several. I think the Dorman is the only one that has all the reduction gears intact.
Anyway, to summarize without using AI, just another vote for "you simply can't buy quality parts anymore".
The irony being my rear mode actuator ('06 Envoy XL) had been working perfectly since April 30th of this year. When I first acquired the vehicle back in fall of 2023 both the rear actuators reduction gears were little more than crumbs of plastic. Replaced both with AC-Delco / "GM GENUINE 1572811" from RA. Then in April I was again confronted with the "tick of death" sound from the rear. Replaced under warranty. Yesterday I had it parked outside for several hours and when I moved it back in the garage was once again confronted with the "tick of death".
My gut tells me these parts are just CCC (actually made in Korea so CKC).
I have a whole pile (4 to be exact) in my parts bin. One Dorman from the other LWB we own that wouldn't calibrate out of the box and three that look like GM OE parts with 'Made In Korea' molded into the cover above the barcode. Of all of these, the first one I opened had copious amounts of grease on the potentiometer portion of the PCB. I think I'm going to try cleaning this off and attempt to make one out of several. I think the Dorman is the only one that has all the reduction gears intact.
Anyway, to summarize without using AI, just another vote for "you simply can't buy quality parts anymore".
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spfautsch
Member
Just wanted to drop in with an anecdotal update. After going through 3 "new" actuators from Rock Auto, all 3 set a code indicating open (B0145-13 / B0428-13) and would not pass the recalibration routine. I started to wonder if there was a wiring issue, but when I would switch positions with the working actuator, the DTC followed the new part. I ended up putting the gears out of one of the "new" parts into the one that failed, cleaned the PCB and resoldered everything.
It's now working, but the moral of the story here is these rectangular actuators are apparently not all compatible. Even ones that came out of a "GM Genuine" box and looked identical to the previous pair that were installed.
My suspicion is one of the "new" GM units was used and returned and then re-sold to me because the contact pads for the wiper had noticeable wear marks. The other GM unit looked new. The first one I bought was chosen b/c it was the most expensive was a GPD branded unit. Those two are going back, I just sincerely hope they don't end up being sold to another GMT370 owner. What a PITA.
It's now working, but the moral of the story here is these rectangular actuators are apparently not all compatible. Even ones that came out of a "GM Genuine" box and looked identical to the previous pair that were installed.
My suspicion is one of the "new" GM units was used and returned and then re-sold to me because the contact pads for the wiper had noticeable wear marks. The other GM unit looked new. The first one I bought was chosen b/c it was the most expensive was a GPD branded unit. Those two are going back, I just sincerely hope they don't end up being sold to another GMT370 owner. What a PITA.
I've been seeing online that such occurrences of switched parts is a problem everywhere, even shops. Just unscrupulous assholes.