Temp Actuator position ranges

[DIYguy]

The temps coming out of my driver side vents are consistently about 10degrees colder than on the passenger side with the AC on (for example if it’s 85F out then the vent would be 55 on the driver vent and 65 on the passenger side)…. Both actuators appear to be working (they raise and lower temp ok). I have manual climate controls.

Does anyone know the range of motion I should expect for full cold to full hot for the passenger temp actuator? Photos below show the “notch” at about 30deg from the line for full cold and -30deg for full hot. I don’t want to just change it if that’s not the issue…





When looking for schematics, I also saw that there is a temp sensor inside the vent. Could that potentially cause this temp differential?

The AC is otherwise working fine; in the past when I had a leak, it was the passenger side that blew cooler than driver side since that’s closer to the evaporator… so it really seems to be a mixing issue.

 

[Mooseman]

You might need to do an HVAC relearn. Pull the HVAC-B fuse for 30 seconds in the rear fuse box, put it back in, then turn the key to RUN but don't start it and don't touch the HVAC controls. Let it do its thing for a couple of minutes while it relearns the actuators.

If that doesn't work, it's likely the actuator is failing. That one looks original so that is quite possible. Without a scanner to be able to command and read actuator positions, there is no way for sure to confirm it.

 

[DIYguy]

I’ll try that. Is there a preferred position or status to set my controls before I pull the fuse (to avoid risk of breaking another working actuator as it recalibrates and potentially “overshoots” the end in the process)?

Another thought… if I removed that actuator, could I manually adjust the shaft for the “flap” in the vent to full cold and confirm if that makes any difference?

 

[Mooseman]

’ll try that. Is there a preferred position or status to set my controls before I pull the fuse (to avoid risk of breaking another working actuator as it recalibrates and potentially “overshoots” the end in the process)?

Nope. Just let 'er rip.

Another thought… if I removed that actuator, could I manually adjust the shaft for the “flap” in the vent to full cold and confirm if that makes any difference?

No. The shaft and actuator are keyed to a specific position. The gear might have skipped or slipped internally.

Post in thread 'HVAC actuator noise'

Oct 20, 2018

Here's a picture of the proper indexing if you install used parts - or for anyone else that finds this thread in the future ! The main gear "notches" line up vertically and smaller
"potentiometer" gear has 2 pins that align horizontally,.... (#'s printed on small gear positioned at the top. )

Pic shows Vent/Floor actuator,.... but all of them are indexed as shown.

• John in RI

• 

And then there's this video. Very descriptive however his are slightly different for full size trucks and has the wrong sensor gear alignment for ours.