MBZmom ...............
(I have to jiggle the ignition key just right to get the heater/AC to work. And then when I do get it to work it goes off by itself.)

This may be a bad ignition switch. The wires may be loose??
Do a search on the board, "ignition switch" you may find an answer. There may be a special tool to remove it.

(Also the tranny every now and then slips.)
You could try changing the fluid and filter. Be sure to drain the torque converter. I’m not sure I would use an additive. I have used a product called trans-x with very good results.
The fluid change should be sufficient.

(I can hear the little motor running but the chair won't budge …..and with a drill moved the seat back ……)
The motor works ??? and the drive cable seems OK ?????
Himmmmmmmmmmm..
Reconnect it to the motor and try to observe what happens.

(Why doesn't the vent in the center console work? You know the one that blows air to the back seat)

Maybe a vacuum servo not working. Disconnected Vacuum line??
Do a search on “center console vent”

_AC