Air stuck on defrosters

[Synna]

I have a 99 park ave. Supercharger ultra and it’s been stuck on the top air vents since I got it. I’ve tried searching the problem and only finding things for the LeSabre. Is there a way to fix it?

 

[HotZ28]

Typical blend door failure!

 

[02LTD2.0]

I had a 1998 Olds 88 that would always blow through the defroster vents. I had a vacuum leak right before the vacuum line goes through the firewall to the HVAC unit. A one and a half inch piece of vacuum hose solved the problem.

 

[HotZ28]

I don't remember if the '99 was vacuum controlled actuators, or electrical servo controlled. Maybe someone here can help clarify.

 

[5.0MX5]

First, the good news. I know what's bad, it's the electric motor driven mode actuator. As you're setting in the car, it's to the right of your right knee, below the radio. At 74 years young (old?) I replaced one this year. So, it's possible, however it was a challenge for me anyway. I'm 6' and 165 lbs and it was a challenge to wiggle into the available work space. Details HERE.

It does seem the recommended replacements are now made of unobtaintum. However the most common thing to fail in mode actuators and other actuators is a large plastic drive gear and you can buy those online. Easy to change.

Good Luck,

RonR