My new to me 02 ETC has the typical problem with one side blowing hotter or colder than the other side. This is an indication of the air blend actuator not moving the blend door to the correct position.
I also have the problem of the HVAC mositure cover (plastic/rubber piece on the firewall) is brittle and falling off whenever it's touched. By the FSM, this requires the motor to be lowered to replace. I have some ideas that may work to install and not lower the motor. Not sure, has anyone else replaced theirs and not lowered the motor? This will be the second project this weeknd if I can get to it.
The first if the air distribution problem.
I have read hundreds of posts, and they typically end with no resolution or one that is not satisfactory for me.
So here goes...one that has a beginning, a middle and a satisfactory end (fingers crossed).
My symptoms are the passenger side blows hot air all the time (yours could be cold, same situation) and there is a vacuum noise on the passenger side which sounds like air being let off every 5 or so seconds. The two symptoms are completely different problems.
The easy one is vacuum. There are 4 vacuum actuators and colored vacuum lines for: park brake release, defrost, recirc and air up/down (which vents the air distributes to). My air distributes up and down fine, so I think one of the other actuators or lines has a small leak. A MityVac test on the vacuum distribution block will tell.
Here is the diagram:
Air blend actuators are a bit more in depth. There are 2 that all work the same way: passenger side, and drivers side. They are located behind the glove box with the passenger's side being on top and the driver's side being on the bottom. My passenger side blend door moves freely and the actuator moved jerkily when I changed the temperature to the extremes. I pulled the actuator and found the bull gear was cracked. Pictures coming soon (I'm charging the good camera).
What didn't work was buying a Dorman actuator off Amazon ($65), slapping it in and "reprogramming" per the FSM. I might have goofed up and pulled the wrong fuse. The actual fuse is labeled comfort and is located in the trunk. I did reset everything on the actuator as I got it, re-installed and pulled the battery leads and shorted them out. Still no re-programming. I watch the actuator move (or not) while changing the temp to extremes.
My plan is to test the door position feedback and the internal position potentiometer in the actuator. Next, I'll pull an idler gear from the actuator, measure the trigger voltage, and vary the door position and actuator position potentiometer to see if I can get the actuator drive motor to move reliably in both direction.
Here is the schematic:
Here is the operations for the air actuators.
Continued...
I also have the problem of the HVAC mositure cover (plastic/rubber piece on the firewall) is brittle and falling off whenever it's touched. By the FSM, this requires the motor to be lowered to replace. I have some ideas that may work to install and not lower the motor. Not sure, has anyone else replaced theirs and not lowered the motor? This will be the second project this weeknd if I can get to it.
The first if the air distribution problem.
I have read hundreds of posts, and they typically end with no resolution or one that is not satisfactory for me.
So here goes...one that has a beginning, a middle and a satisfactory end (fingers crossed).
My symptoms are the passenger side blows hot air all the time (yours could be cold, same situation) and there is a vacuum noise on the passenger side which sounds like air being let off every 5 or so seconds. The two symptoms are completely different problems.
The easy one is vacuum. There are 4 vacuum actuators and colored vacuum lines for: park brake release, defrost, recirc and air up/down (which vents the air distributes to). My air distributes up and down fine, so I think one of the other actuators or lines has a small leak. A MityVac test on the vacuum distribution block will tell.
Here is the diagram:

Air blend actuators are a bit more in depth. There are 2 that all work the same way: passenger side, and drivers side. They are located behind the glove box with the passenger's side being on top and the driver's side being on the bottom. My passenger side blend door moves freely and the actuator moved jerkily when I changed the temperature to the extremes. I pulled the actuator and found the bull gear was cracked. Pictures coming soon (I'm charging the good camera).
What didn't work was buying a Dorman actuator off Amazon ($65), slapping it in and "reprogramming" per the FSM. I might have goofed up and pulled the wrong fuse. The actual fuse is labeled comfort and is located in the trunk. I did reset everything on the actuator as I got it, re-installed and pulled the battery leads and shorted them out. Still no re-programming. I watch the actuator move (or not) while changing the temp to extremes.
My plan is to test the door position feedback and the internal position potentiometer in the actuator. Next, I'll pull an idler gear from the actuator, measure the trigger voltage, and vary the door position and actuator position potentiometer to see if I can get the actuator drive motor to move reliably in both direction.
Here is the schematic:

Here is the operations for the air actuators.
Continued...
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