If you get cold air from the center vens sometimes and blower control is iffy, I think the more likely culprit is a tired ACC PBU.

To remove the panel that houses the ACC controls and the bank of switches above, remove the 2 screws along the bottom of panel exposed when the radio is out. The screws point upwards. Pull down on the panel as you pull it out. As you remove and replace the panel, mind the fiber optic cables that illuminate the switches.

Sixto
95 S420
87 300SDL