I finally replaced my temperature actuators and they kind of work now. They will actuate but with zero correlation to the temp chosen on the dial. I can get hot and cold out of both sides, but not because i asked it to. I did the relearn procedure around 10 times but to no avail. I think it's the AC control unit but I don't know. Anyone have any advice or suggestions? Thanks in advance.
Replaced Temp Actuators, Still not Working
- Thread starter triplevision
- Start date
Mooseman
Moderator
Specifically which actuators? I have read the passenger side temperature blend door actuator requires either removing the heater module or cutting some dash frame.
For the first time ever owning it I have AC but i now don't have a reliable way to switch back to heat. If I put the temp dial in the middle for instance, it will go full lock to whatever the vehicle decides. I have full hot (sometimes) and full cold (sometimes) and nothing in between. And if it gets locked in either hot or cold, it won't change with the dials at all to the other extreme. I have to start the truck with the desired temp or i am screwed for the drive.
I guess a couple of questions... what was your "relearn" procedure? IF you have easy access to one of the actuators / connectors, can you pull the connector and get out a meter and measure what's happening on the control signal wire (voltage... 2.5 at rest and or 0 / 5v depending on what it does)? Further, if you can, also measure the position sensor wire (resistance)? There are 5 wires in the connector, 5v, 12v, low reference, position, and control. sorry, I don't have the connector diagram at this point.
I am guessing your position readings aren't any good.... missing a reference or power signal.... best guess would be, low reference.
Of course, what vehicle year might help.
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Mooseman
Moderator
Yes they are.
I'm thinking that the actuators are defective beyond just the broken gears. Without a bi-directional scan tool to see requested and actual position, you're just taking shots in the dark.
I'm all for going cheap but sometimes you have to spend a little more.
I have the ability to read the actuator positions in my 2002 Automatic system with Torque Pro, Car Scanner, or equivalent but I cannot remember if I ever got the manual system figured out.
If it were only that simple!
It is more complex than that.
The HVAC modules do not support the mode that Torque uses to read live data. So even though I know the PID numbers I cannot use them to read the data.
So for my CJ2 automatic HVAC control module I scanned the memory of the device and with testing I found the memory addresses where the PID data is stored. I can use Torque to directly read the memory address and that is how I get the data.
I don't remember if I ever scanned the two manual HVAC modules I have. And even if I did I am pretty sure I never tried to find the data since I only have the modules and no other parts of a manual control system.
I did come up with a way to use the PID numbers to get the data but that method is equally complex and I have only tested it iny automatic CJ2 HVAC systems.
ChrisinVictoria
Member
- Apr 26, 2014
- 53
I found that the replacement actuators threw a code and had different circuitry. After in and out several times I just took the gears out of the new one and installed them in the original. It worked for me. My original fault was improper mode control and the actuator would bang for 10 seconds on cold start.
For my 2002 the original drivers side temperature blend door is #16164972. The passenger blend door actuator original is #16163982. Mine was an early build date of 10/01.
I would double check that the replacement actuators are the correct part numbers for your original actuators part numbers. All too often it is assumed they are all the same across the years but they are not.
So, after living with it for some time now, I need to describe the hilarious ridiculousness of these new actuators. I cannot find a way to adjust the passenger side temp; it's just stuck on hot. But the driver side can be adjusted...with the passenger side dial. If I have the driver and passenger side set to full cold, i get hot air from both sides. If i adjust the passenger side to 3/4 hot while the driver side is set to cold, the driver side will blow cold air, with no adjustment to passenger temp. I at one point had the passenger side to cold but when i adjusted the temp one cold morning, all i got was hot from the passenger side since then. I feel like I am losing my mind.
Mooseman
Moderator
Maybe at this point I would suspect the HVAC module/panel. I'd just get a used one from a pick-n-pull yard. Don't get a new one as it would require programming and is too expensive. A used one from a same year truck would swap right in.
That's been my thought from the get-go. This might be very niche information, but, does anyone know if the passenger side temp dial have a backlight to it? The driver's side temp dial on mine has a backlight but the passenger side does not light up.
Mooseman
Moderator
That graphic illustrates my previous comment and question about the part number the OP actually used. The part number listed in that graphic for the defrost and drivers temp does NOT fit a 2002.
The correct GM part# for a 2002 drivers side temp actuator is 89018375.
The correct part number for a 2002 passenger side temp actuator is 89018365.