H3 HVAC control unit
#41
01-19-2020, 12:52 PM
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.
https://www.youtube.com/watch?v=vWBGKfl7k24
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.
https://www.youtube.com/watch?v=vWBGKfl7k24
1) Put the 68 ohm 1/2 watt resistor back in line with the 5V lead coming off of the back of the HVAC controller. Recalibrated, and this fixed the temperature issue. This tells me that even this "new" HVAC part number has the voltage problem where it pops slightly out of range. The mode issue persisted.
2) I disconnected all of the actuators and tested the pins on their connector harnesses. I suspected that both pins 2 and 3 should have around 5 volts coming off of them. For all three of the temp/mode actuators pin 3 should be 5V and pin 2 is the position signal. For the right/left temperature actuators I was getting 5v for both pins. For the mode door actuator I was getting 5v coming off of pin 3, but not pin 2. I figured I had a solid place to look at this point.
3) Per my reply last night you can keep the right connector on the HVAC controller and disconnect the left one to test the pins for the actuators. Power comes into the HVAC controller from that right side connector, and the left is just the actuator signals. Pin b is the mode door position signal, pin d is the right temp door position signal, and pin e is the left temp door position signal. All three of those were reading close to 5V. I then cut pin b and tested the voltage at the wire, and it was 5V. Someplace between that point and where it connects to the mode door actuator there must be a short or something. Likely from the radio install I had done 3 years ago, but who knows. Like I said this was working intermittently, but with all the wires behind the new radio I had installed (back-up camera, SiriusXM/etc) maybe this short was just happening sometimes. Regardless, I spliced a new wire from the back of the harness plugged into the left side of the HVAC controller to pin 2 on the mode door actuator's harness. Recalibrated and voila. The recalibration took around a minute like you said it should, and everything works as normal.
4) Cleaned everything up, and did a happy dance.
Thank you Hummerz VERY much for all of the assistance. I will report back in a few weeks once I know this fix keeps working
#43
01-30-2020, 09:05 PM
Drumroll. I believe I have it fixed! Here is what I did this morning:
1) Put the 68 ohm 1/2 watt resistor back in line with the 5V lead coming off of the back of the HVAC controller. Recalibrated, and this fixed the temperature issue. This tells me that even this "new" HVAC part number has the voltage problem where it pops slightly out of range. The mode issue persisted.
2) I disconnected all of the actuators and tested the pins on their connector harnesses. I suspected that both pins 2 and 3 should have around 5 volts coming off of them. For all three of the temp/mode actuators pin 3 should be 5V and pin 2 is the position signal. For the right/left temperature actuators I was getting 5v for both pins. For the mode door actuator I was getting 5v coming off of pin 3, but not pin 2. I figured I had a solid place to look at this point.
3) Per my reply last night you can keep the right connector on the HVAC controller and disconnect the left one to test the pins for the actuators. Power comes into the HVAC controller from that right side connector, and the left is just the actuator signals. Pin b is the mode door position signal, pin d is the right temp door position signal, and pin e is the left temp door position signal. All three of those were reading close to 5V. I then cut pin b and tested the voltage at the wire, and it was 5V. Someplace between that point and where it connects to the mode door actuator there must be a short or something. Likely from the radio install I had done 3 years ago, but who knows. Like I said this was working intermittently, but with all the wires behind the new radio I had installed (back-up camera, SiriusXM/etc) maybe this short was just happening sometimes. Regardless, I spliced a new wire from the back of the harness plugged into the left side of the HVAC controller to pin 2 on the mode door actuator's harness. Recalibrated and voila. The recalibration took around a minute like you said it should, and everything works as normal.
4) Cleaned everything up, and did a happy dance.
Thank you Hummerz VERY much for all of the assistance. I will report back in a few weeks once I know this fix keeps working
1) Put the 68 ohm 1/2 watt resistor back in line with the 5V lead coming off of the back of the HVAC controller. Recalibrated, and this fixed the temperature issue. This tells me that even this "new" HVAC part number has the voltage problem where it pops slightly out of range. The mode issue persisted.
2) I disconnected all of the actuators and tested the pins on their connector harnesses. I suspected that both pins 2 and 3 should have around 5 volts coming off of them. For all three of the temp/mode actuators pin 3 should be 5V and pin 2 is the position signal. For the right/left temperature actuators I was getting 5v for both pins. For the mode door actuator I was getting 5v coming off of pin 3, but not pin 2. I figured I had a solid place to look at this point.
3) Per my reply last night you can keep the right connector on the HVAC controller and disconnect the left one to test the pins for the actuators. Power comes into the HVAC controller from that right side connector, and the left is just the actuator signals. Pin b is the mode door position signal, pin d is the right temp door position signal, and pin e is the left temp door position signal. All three of those were reading close to 5V. I then cut pin b and tested the voltage at the wire, and it was 5V. Someplace between that point and where it connects to the mode door actuator there must be a short or something. Likely from the radio install I had done 3 years ago, but who knows. Like I said this was working intermittently, but with all the wires behind the new radio I had installed (back-up camera, SiriusXM/etc) maybe this short was just happening sometimes. Regardless, I spliced a new wire from the back of the harness plugged into the left side of the HVAC controller to pin 2 on the mode door actuator's harness. Recalibrated and voila. The recalibration took around a minute like you said it should, and everything works as normal.
4) Cleaned everything up, and did a happy dance.
Thank you Hummerz VERY much for all of the assistance. I will report back in a few weeks once I know this fix keeps working
Just joined this forum mainly for this reason, I too will try this same procedure , I have both a Mexico and Portugal module. I am also a Colorado owner and as with clone part issues the OEM battery terminals have been known to cause issues randomly as I experienced with the H3s "step brother".
As for the scarcity of new modules I'm only guessing that GMs parts strike may have somehow affected AC Delco as well as the OEM, I actually called AC Delco and their system said same as retailer " no available date".
#44
01-30-2020, 09:18 PM
Just joined this forum mainly for this reason, I too will try this same procedure , I have both a Mexico and Portugal module. I am also a Colorado owner and as with clone part issues the OEM battery terminals have been known to cause issues randomly as I experienced with the H3s "step brother".
As for the scarcity of new modules I'm only guessing that GMs parts strike may have somehow affected AC Delco as well as the OEM, I actually called AC Delco and their system said same as retailer " no available date".
As for the scarcity of new modules I'm only guessing that GMs parts strike may have somehow affected AC Delco as well as the OEM, I actually called AC Delco and their system said same as retailer " no available date".
Thread
Thread Starter
Forum
Replies
Last Post