Chrysler Repair: Heating and Electrical:96 Sebring Convert., fuse box, private option

Question
QUESTION: 1.  I cannot get the heat/ac fan control knob to respond to any position (as in the air only blows from the defog vent near winshield).  Any fix to get the knob to respond to floor vent setting, middle vents, etc.?
2.  Tac works periodically and dash lights work periodically.  Any fixes?
Thanks.

ANSWER: Hi Tom,
I need to know the year and model of the car that you have.
Also, please don't use the Private option as no one else can learn from what we exchange.
Thanks,
Roland

---------- FOLLOW-UP ----------

QUESTION: Sorry- it is a 1996 Sebring Convertible.

Answer
Hi Tom,
All those issues have a common connection: they are all mediated by the body computer. It is possible that because of the convertible design that you have gotten some water leakage from the lower corner of the windshield on the drivers side and that has dripped on the plugs of the body computer which can short out some of the data bus communication between the body computer/dash/dash lights/heater-AC mode door actuator... You might find that when you have a functioning tach/lights that the mode door will also work (that is the door which directs the air to different outlets). Were that the case, it would confirm this theory.
You might do well to look at the back side of the fuse box that is under the dash on the drivers side where you will find the body computer mounted as part of the box. Buy a spray can of electronic circuit cleaner, remove the plugs to the body computer and spray the sockets and pins, then let it evaporate and plug it together again. Before replacing the plugs,  separate the fuse box from the body module (release two latches, remove two screws) and similarly spray the interface between the body module and the fuse box. Then put it all back together.
To remove the fuse box/body control module: Remove the end cap from the driver's door side of the instrument panel, remove the center console bezel, remove the instrument cluster hood, remove the under dash silencer panel on the lower edge of the driver's side. Then you can remove the plugs from the box. Remove the three mounting screws, then pull straight down. Then remove the body module plugs, etc.
Roland