I was just about to post this issue. I have found that all the heater levers can be opperated with a thin screwdriver. All my lever are missing the handles (some are missing even 10-15% of the disks.
Nevertheless, I was able to slide mine in both directions easily by inserting a thin flat edge screwdriver between chrome slots and pushing on the notches thatt are in each disk, there are about 3 notches on each disk; and I was able to push with some pressure with no promlem [as i feared they might crumble], as there is enough rotation to get to next notch. This sure beats $400+ in parts, $500+ in labor or 8+ hours of labor.
The manual shows all settings; from memory you should:
-Push top left lever all way left (for air to wind shield)
-push bottom 2 lever towards center (for cold)
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Top left
- opens fresh air flap in front of windshield
Top right
- redirects air flow (windshild/floor)
Bottom left
- opens main heat flap (driver's side) and heater core valve
Bottom right
- opens secondary heat flap (passenger side)