Part is made in Mexico. Tried all 3 again today, and no luck. This manual calibration only blinking once is really bothering me. This part is definitively brand new - zero signs of wear on it. Ugh. So annoyed, I just want this working.

 

That's right. Recheck/clean connectors and check wiring make sure all wiring is oem. Other than that you will need a meter and back probe wires during operation.

 

its all oem wiring. I’m the original owner and know all the work done on it. The only thing non oem is a new head unit stereo, and the interior blue led lighting on it. I’ve got a nice multi meter. I assume I can start checking voltage coming off of the leads on the back of the connectors somehow during operation?

 

I'm just speaking of the hvac wiring, make sure no splices into those wires, which could affect voltage to the controller. I'm sure you already checked all the hvac fuses/relay, correct?

 

actuator calibration takes around a minute to complete:

 

so I’m back at it again. I pulled and reseated any fuse that seemed like it might have anything to do with hvac or voltage regulation. When I restarted the control unit it seems to calibrate fully. Same issue though. I’m testing that light blue / black wire that some people have added a resistor to. I had one but removed it when I put the new control unit in. I’m not a pro at this, but when I touch my positive multimeter probe to that wire, and then the negative to a bolt or something, I get 4.8v. (Just updated this post. I had the range set wrong). 4.8 should be within specs according to the hvac repair manual for h3.

 

Should be 5v, yet could be within specs. Adjust your dials back and forth make sure you are getting the actuators to move/air/temp flow as directed.

 

When I move the temp dial one click from all the way cold the right temp actuator doesn't move at all, and the left moves all the way. When I move the mode one click from full face the mode actuator moves all the way. I can get my head under and see them moving. I have the 90 page HVAC manual that I am using to see which pins on the harnesses are for which functions. As you're looking at the front of the HVAC controller the harness on the left side of it has a low ref, 5v ref, and then the control signals for all of the actuators. You can disconnect that one and just leave the right harness on since all the power comes in from that one, and all the other pins on that don't have anything to do with the actuators. It has battery positive/ground, AC request signal, rear defog, etc. Anyway, leaving that right harness connected and disconnecting the left I can hook my multimeter to each of the pins on the back of the HAV controller for the left side harness. I basically either get 4.8V or 0V from all of those pins. I'm not sure how to take the testing with my multimeter to the next level though

Nothing in this manual indicates what would just cause those actuators to flip all the way to the opposite end. I have heard about this emergency mode, but what actually causes that to happen?

I found this from the GM bulletin about the issue:
"Some customers may complain that the temperature will go to full hot when they turn the temperature control one click off of full cold. The control head is defaulting to Emergency Mode (this provides HOT air for safety reasons which would be available to clear the windshield in Defrost mode). This will happen if the feedback voltage for the air temperature actuators are out of range."


BTW - I really appreciate you going back-and-forth on this with me. It is frustrating, and I don't think taking it into a shop that isn't well versed in this problem is going to do anything.

 

Read again:

This will happen if the feedback voltage for the air temperature actuators are out
of range.

You need to check the blenddoor actuator, should open close @ command, and make sure there is a clean connection and wiring is proper back to the controller. If you are sure all is good, give it some time to relearn. Btw, can you verify the actuator is properly reset before install.

 

I didn't do that before install, but I do remember checking that the shaft was oriented properly when I did the install back in October or November. The odd thing is that this was all functioning properly for a little bit after I put the new actuators in, and then stopped. Then I got it calibrated again and it worked for about half of my drive from Houston to Breckenridge, CO for xmas before it stopped functioning properly again.