Originally Posted by willwren
Don't pull the glovebox yet. Read the codes, report back here. There MAY be no need to pull the box after reading/clearing the code.
Reading the ECC error codes is pretty painless on the 93. Not a bad idea to go ahead and do it. I'm willing to bet it tells you the ECC needs to be calibrated or that your programmer may be bad. And chances are very slim it’* the programmer.
Boosty is probably right – disconnecting the power to the ECC seems to be the death knell for the gear in the airmix actuator, or at least contributes to it. Chances are yours is just beginning to auger in. If you ignore it for a couple weeks it may come back to normal. Mine did. Until I disconnected the battery a couple more times and the gear finally split over 75% through.
Based on the scenario you’ve given, I’d place money on a failing actuator. I dorked around with mine enough to think I recognize the symptoms. Spent lots of time watching it do its thing. If you decide to yank the glovebox (easy enough to do) and watch the action and you see anything but nice, smooth movement of the air mix door arm, you’ve found your huckleberry…a failing actuator.
Follow WillWren’* advice, though, and read those codes first. It’* actually kinda fun.
One more thing - is your heater output somewhat random? Sometimes it'* cool, then when you shut off and restart the car you might get hot or lukewarm air? Sure sign of a dying air mix actuator there!